Polypeptides having human IGG cleavage activity

Abstract

The present disclosure provides polypeptides having human IgG cleavage activity and having 80% or less amino acid sequence identity to the amino acid sequence of IdeS. Polypeptides disclosed herein have significantly reduced binding to anti-IdeS antibodies, such as, pre-existing anti-IdeS antibodies present in a human subject previously exposed to IdeS. These polypeptides may be used for treating a human subject suffering from a disease mediated by IgG antibodies, which subject may or may not have pre-existing anti-IdeS antibodies; and for preparing a fragment of human IgG antibody. Some of the polypeptides provided herein selectively cleave human IgG1, 3, and 4 while showing no or low activity in cleaving human IgG2. Some of the polypeptides provided herein selectively cleave human IgG3 and 4 while showing low activity in cleaving human IgG1 and 2. Some of the polypeptides provided herein selectively cleave human IgG4 while showing no or low activity in cleaving human IgG1-3.

Description

[0001] Atty Docket No.: NHWK-003WO POLYPEPTIDES HAVING HUMAN IGG CLEAVAGE ACTIVITY CROSS-REFERENCE This application claims the benefit of U.S. Provisional Patent Application No. 63 / 585,929, filed September 27, 2023, which application is incorporated herein by reference in its entirety. INCORPORATION BY REFERENCE OF SEQUENCE LISTING XML A Sequence Listing is provided herewith as a Sequence Listing XML, “NHWK- 003WO_SEQ_LIST” created on August 28, 2024, and having a size of 93,255 bytes. The contents of the Sequence Listing XML are incorporated by reference herein in their entirety. INTRODUCTION The bacterium Streptococcus pyogenes is a common human pathogen. To avoid the human immune system, the bacterium produces several enzymes that help to evade the immune system by cleaving human IgGs. IgG-degrading enzyme of Streptococcus pyogenes (IdeS) or streptococcal Mac-1, and a related variant, Mac-2, are cysteine proteases secreted from S. pyogenes that cleave IgG within the lower hinge region, yielding F(ab’)2 and Fc fragments. The cleavage of IgG results in rapid clearance of the F(ab’)2 fragment and eliminates both antibody- dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) due to the IgG. IdeS is highly specific for IgG and cleaves all human IgG subclasses. IdeS (also known as Imlifidase) is used in the clinic as a pre-treatment for kidney transplantation in highly sensitized patients. In addition, there is interest in utilizing IdeS for other antibody-driven autoimmune diseases where complete depletion of IgG would remove pathogenic antibodies. However, S. pyogenes infections are common in humans, consequently there are pre-existing anti-drug antibodies (ADA) to IdeS present in human serum. The pre- existing ADA has been reported to neutralize IdeS activity and increase IdeS clearance. While IdeS can be dosed at a higher concentration to overcome pre-existing ADA, subsequent doses are limited due to the highly immunogenic nature of this bacterial protein and the memory B-cell response. To avoid pre-existing ADA, there is a need for new endopeptidases that maintain IdeS- Atty Docket No.: NHWK-003WO like activity but are immunologically distinct from IdeS. SUMMARY The present disclosure provides polypeptides and compositions having human IgG cleavage activity in the human subject. The polypeptides of the present disclosure comprise an amino acid sequence having at least 85% sequence identity to the amino acid sequence set forth in SEQ ID NO:2 and 80% or less sequence identity to the amino acid sequence of IdeS having the amino acid sequence set forth in SEQ ID:1. In some embodiments, the polypeptides disclosed herein do not show significant binding to anti-IdeS antibodies, such as, pre-existing anti-IdeS antibodies in a human subject, e.g., anti- IdeS antibodies present in a serum sample obtained from a human subject. In some embodiments, the polypeptides disclosed herein show significantly reduced binding to preexisting anti-IdeS antibodies in human serum as compared to binding of IdeS to the existing anti-IdeS antibodies in human serum. In one embodiment, the polypeptide comprises the amino acids: (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and / or (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232. In another embodiment, the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289. In still another aspect, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289. In another embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; Atty Docket No.: NHWK-003WO and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202. In another embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307. In a further embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307. In another embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; Atty Docket No.: NHWK-003WO the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307. In yet another embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and amino acid N at position 307; and the amino acid N at position 187. In one embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and amino acid N at position 307; and the amino acid N at position 187. In another embodiment, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, N at position 232; the amino acid N at position 307; and the amino acid N at position 187. The present disclosure further provides methods for treating a human subject previously treated with IdeS or exposed to IdeS via Streptococcus pyogenes infection, and methods for treating a human subject suffering from a disease mediated by IgG antibodies by administering the polypeptides or the compositions to the human subject and further provides methods of preparing a fragment of human IgG antibody. The present disclosure also provides nucleic acids encoding these polypeptide and recombinant expression vectors comprising the nucleic acids. The present disclosure provides host cells comprising the nucleic acids or the recombinant expression vectors. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 depicts the sequence alignment of IdeS (SEQ ID NO: 1), with the Mac family cysteine Atty Docket No.: NHWK-003WO endopeptidase from S. canis, referred to as IdeCanis (SEQ ID NO: 2). The upper horizontal bar marks stretches of amino acids that are identical between the two sequences. The amino acids in the active sites K55, C65, H233, D255, and D257 are annotated and the amino acids forming loops M1-M4 are indicated. FIG.2 depicts the sequence alignment of canine IgG heavy chain constant regions of IgG A, IgG B, IgG C, and IgG D (SEQ ID NOs:62-65, respectively), with human heavy chain constant regions of IgG1, IgG2, IgG3, and IgG4 (SEQ ID NOs:58-61, respectively). The height of the horizontal bars above the alignment is proportional to the level of conservation of amino acid similarity between the sequences. The IdeS cleavage site is marked with an arrow and the corresponding substrate residues labeled P2, P1, P'1, P'2. FIG. 3A depicts SDS-PAGE analysis of IdeS and IdeCanis after purification with Ni-NTA capture of His-tagged proteins. FIG 3B depicts the analytical size exclusion chromatography (SEC) traces of IdeS and IdeCanis after purification with Ni-NTA capture of His-tagged proteins. FIG.4A depicts a representation of the competitive anti-drug antibody (ADA) ELISA setup. FIG. 4B shows the percentage of ADA that binds to inactive mutants (C65S) of IdeS and IdeCanis. The percentage of ADA bound in solution was determined by using the formula (1 / (variant signal / IdeS signal)), where IdeS-C65S is set to 100%. FIG.5 depicts the IgG cleavage pattern of IdeS (panel A) and IdeCanis (panel B) using SDS- PAGE visualization. Lanes 1-4 are controls of protease, human IgG1, mouse IgG1, and monkey IgG loaded for reference. Lanes 5-8 are the human IgG1, IgG2, IgG3, and IgG4 with protease added. Lanes 9-12 are the mouse IgG1, IgG2a, IgG2b, and IgG3 with protease added. Lane 13 is monkey IgG with protease added. The full-length heavy chain (HC), protease, cleaved HC fragments (F(ab’)2 and Fc), and light chain (LC) are annotated. FIG.6 depicts the crystal structure of IdeS in complex with Fc domain of IgG1 (PDB 8A47)(Sudol et al., 2022). The Fc hinge and the IdeS active site are annotated with arrows. The loops, M1, M2, M3, and M4, that were targeted in IdeCanis for mutation are highlighted with spheres on the backbone of the amino acid chain. FIG. 7 shows the visualization of the SDS-PAGE gels for a subset of IdeCanis variant enzyme reactions with human immunoglobulins. Lanes 1-4 on each gel contains the IdeCanis Atty Docket No.: NHWK-003WO variant after incubation with human IgG1, IgG2, IgG3, IgG4, respectively. The full-length heavy chain (HC), protease, cleaved HC fragments (F(ab’)2 and Fc), and light chain (LC) are annotated to the left of the gels. FIG. 8 shows the evaluation of IdeCanis protease for degradation of human immunoglobins, with the EC50 curves for different IdeCanis variants with each human IgG subclass. The response for each protease was normalized for the comparison plot. The antibody on the plate was measured with an anti-Fc antibody, so when the protease cleaves the target antibody, the signal will lower due to the loss of the Fc after cleavage. The curves were fit to non- linear regression absolute EC50 curves. FIG.9 depicts the percent of pre-existing ADA in pooled human serum that interacts with IdeCanis variants. The percentage of ADA bound in solution was determined by using the formula (1 / (variant signal / IdeS signal)), where IdeS-C65S is set to 100%. DETAILED DESCRIPTION The present disclosure provides polypeptides which have been engineered to have human IgG cleavage activity. These polypeptides were generated by engineering a polypeptide comprising amino acid sequence set forth in SEQ ID NO: 2 and lacking human IgG cleavage activity. The polypeptides disclosed herein may be used for treating a human subject suffering from a disease mediated by IgG antibodies. Polypeptides disclosed herein may be also used for preparing a fragment of human IgG antibody. Polypeptides disclosed herein may be used for treating a human subject having anti-IdeS antibodies due to previous treatment with IdeS or exposure to IdeS due to S. pyogenes infection. Also provided herein is a method for treating a human subject previously exposed to IdeS by, e.g., an infection by S. pyogenes and / or treatment with IdeS. The method may include administering to the human subject an effective amount of a polypeptide of the present disclosure or a composition of the present disclosure. Also provided herein is a method for treating a human subject suffering from a disease mediated by IgG antibodies. The method may include administering a polypeptide of the present disclosure or a composition of the present disclosure to the human subject. Also provided herein is a method of treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, comprising contacting Atty Docket No.: NHWK-003WO the blood with a polypeptide of the present disclosure. Further provided herein is a method of preparing a fragment of human IgG antibody. The method may include contacting the human IgG antibody with a polypeptide of the present disclosure and the polypeptide cleaves Fc hinge of the IgG antibody to generate a Fab fragment and a Fc fragment. The present disclosure provides nucleic acids encoding polypeptide of interest and recombinant expression vectors comprising the nucleic acids. The present disclosure also provides host cells comprising nucleic acids of interest or recombinant expression vectors of interest. These and other objects, advantages, and features of the invention will become apparent to those persons skilled in the art upon reading the details of the compositions and methods as more fully described below. Before the present methods and compositions are described, it is to be understood that this invention is not limited to particular method or composition described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein Atty Docket No.: NHWK-003WO can be used in the practice or testing of the present invention, some potential and preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. It is understood that the present disclosure supersedes any disclosure of an incorporated publication to the extent there is a contradiction. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. Any recited method can be carried out in the order of events recited or in any other order which is logically possible. It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a ligand” includes a plurality of such ligands and reference to “the peptide” includes reference to one or more peptides and equivalents thereof, e.g., polypeptides, known to those skilled in the art, and so forth. The transitional term “comprising” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. The transitional phrase “consisting of” excludes any element, step, or ingredient that is not specified. The transitional phrase “consisting essentially of” defines the scope to the specified elements, materials or steps and those that do not materially affect the basic and novel characteristics of the invention. As used herein, the terms “IdeS” or “Mac”, refer to a cysteine protease secreted by the important human pathogen Streptococcus pyogenes. IdeS / Mac cleaves the hinge region of human IgG with high specificity and thereby interferes with phagocytic killing. Enzymatic characterization of IdeS / Mac suggests that the high substrate specificity is most likely due to a secondary interaction with a binding site located in the CH2 or CH3 domains of IgG (Vincents et al., 2004). A recent study demonstrated that antibodies from patients with S. pyogenes infections could neutralize the activity of IdeS / Mac and affect streptococcal survival in human blood (Åkesson et al., 2006). In the present disclosure, “IdeS” is a protease enzyme comprising the amino acid sequence set forth in SEQ ID NO:1. Atty Docket No.: NHWK-003WO As used herein, the term "AAV" is an abbreviation for adeno-associated virus, and may be used to refer to the virus itself or derivatives thereof. The term covers all subtypes and both naturally occurring and recombinant forms, except where specified otherwise. The abbreviation "rAAV" refers to recombinant adeno-associated virus, also referred to as a recombinant AAV vector (or "rAAV vector"). The term “AAV” includes AAV type 1 (AAV-1), AAV type 2 (AAV-2), AAV type 3 (AAV-3), AAV type 4 (AAV-4), AAV type 5 (AAV-5), AAV type 6 (AAV-6), AAV type 7 (AAV- 7), AAV type 8 (AAV-8), AAV type 9 (AAV-9), avian AAV, bovine AAV, canine AAV, equine AAV, primate AAV, non-primate AAV, and ovine AAV. “Primate AAV” refers to AAV isolated from a primate, “non-primate AAV” refers to AAV isolated from a non-primate mammal, “bovine AAV” refers to AAV isolated from a bovine mammal (e.g., a cow), etc. As used herein, the term "rAAV vector" refers to an AAV vector comprising a polynucleotide sequence not of AAV origin (i.e., a polynucleotide heterologous to AAV), typically a sequence of interest for the genetic transformation of a cell, such as, a nucleic acid encoding an engineered autoantigen or a hypoimmunogenic biotherapeutic described herein. In general, the heterologous polynucleotide is flanked by at least one, and generally by two AAV inverted terminal repeat sequences (ITRs). The term rAAV vector encompasses both rAAV vector particles and rAAV vector plasmids. As used herein, the term "therapeutically effective dose or amount" of a pharmaceutical compound, as described in this disclosure, is intended an amount that, when administered as described herein, brings about a positive therapeutic response in treatment of a disease. The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the condition being treated, the particular drug or drugs employed, mode of administration, and the like. An appropriate "effective" amount in any individual case may be determined by one of ordinary skill in the art using routine experimentation, based upon the information provided herein. As used herein, the term "pharmaceutically acceptable excipient or carrier" refers to an excipient that may optionally be included in the compositions of the present disclosure and that causes no significant adverse toxicological effects to a patient. As used herein, the term "pharmaceutically acceptable salt" includes, but is not limited to, amino acid salts, salts prepared with inorganic acids, such as chloride, sulfate, phosphate, Atty Docket No.: NHWK-003WO diphosphate, bromide, and nitrate salts, or salts prepared from the corresponding inorganic acid form of any of the preceding, e.g., hydrochloride, etc., or salts prepared with an organic acid, such as malate, maleate, fumarate, tartrate, succinate, ethylsuccinate, citrate, acetate, lactate, methanesulfonate, benzoate, ascorbate, para-toluenesulfonate, palmoate, salicylate and stearate, as well as estolate, gluceptate and lactobionate salts. Similarly, salts containing pharmaceutically acceptable cations include, but are not limited to, sodium, potassium, calcium, aluminum, lithium, and ammonium (including substituted ammonium). As used herein, the term “autoimmune disease” or “autoimmune disorder” refers to a malfunctioned immune system which mistakenly attacks healthy cells, tissues, and organs. In other words, the autoimmune diseases or disorders are caused when the immune system destroys native tissues, cells, or biomolecules by, e.g., mounting an immune response to self- antigens. These attacks affect any part of the body, weakening bodily function and even turning life-threatening. For example, the autoimmune disease or disorder may be pemphigus vulgaris, celiac disease, primary biliary cholangitis, membranous nephropathy, rheumatoid arthritis, Systemic lupus erythematosus, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, psoriasis, hidradenitis suppurativa, uveitis, or juvenile idiopathic arthritis. Immune disorders are often treated with systemic immune suppression, e.g., by administering antibodies, steroids, gene therapy, etc. The treatment methods disclosed herein may be combined with such systemic immune suppression. As used herein, the term "antibody" encompasses polyclonal antibodies, monoclonal antibodies, hybrid (chimeric) antibody molecules (see, for example, Winter et al. (1991) Nature 349:293-299; and U.S. Pat. No. 4,816,567), F(ab′)2 and F(ab) fragments, Fv molecules (noncovalent heterodimers, see, for example, Inbar et al. (1972) Proc Natl Acad Sci USA 69:2659- 2662; and Ehrlich et al. (1980) Biochem 19:4091-4096), single-chain Fv molecules (scFv) (see, e.g., Huston et al. (1988) Proc Natl Acad Sci USA 85:5879-5883), nanobodies or single-domain antibodies (sdAb) including VHH antibodies which include the antigen binding fragment of heavy chain only antibodies, e.g., a Camelidae antibody (see, e.g., Wang et al. (2016) Int J Nanomedicine 11:3287-3303, Vincke et al. (2012) Methods Mol Biol 911:15-26, dimeric and trimeric antibody fragment constructs, minibodies (see, e.g., Pack et al. (1992) Biochem 31:1579-1584; Cumber et al. (1992) J Immunology 149B:120-126), humanized antibody molecules (see, e.g., Riechmann et Atty Docket No.: NHWK-003WO al. (1988) Nature 332:323-327; Verhoeyan et al. (1988) Science 239:1534-1536; and U.K. Patent Publication No. GB 2,276,169, published 21 Sep. 1994), and any functional fragments obtained from such antibody molecules, wherein such fragments retain specific-binding properties of the parent antibody molecule. As used herein, the terms “treatment”, “treating” and the like are used herein to generally mean obtaining a desired pharmacologic and / or physiologic effect. The effect may be therapeutic in terms of a partial or complete cure for a disease and / or adverse effect attributable to the disease. “Treatment” as used herein covers any treatment of a disease in a mammal, and includes: (a) inhibiting the disease, i.e., arresting its development; or (b) relieving the disease, i.e., causing regression of the disease. The therapeutic agent may be administered during or after the onset of disease. The treatment of ongoing disease, where the treatment stabilizes or reduces the undesirable clinical symptoms of the patient, is of particular interest. As used herein, the terms “individual,” “subject,” “host,” and “patient,” are used interchangeably herein and refer to any mammalian subject for whom diagnosis, treatment, or therapy is desired, particularly humans. The term “significantly” is herein used in its usual meaning in the field of statistics (e.g., t test, z test, chi squared value, or F ratio, etc.), i.e., for comparing a value to another one, and determining whether these values differ from each other. The term “significantly” hence encompasses the fact that the skilled person may take into account the standard deviation (if any), which measures the amount of spread of data in a frequency distribution. The desired p value is usually set at an alpha level of 5%, or at the more stringent alpha level of 1%. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual aspects described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several aspects Atty Docket No.: NHWK-003WO without departing from the scope or spirit of the present methods. Any recited method can be carried out in the order of events recited or in any other order that is logically possible. Polypeptides having human IgG cleavage activity Disclosed herein are polypeptides having human IgG cleavage activity. These polypeptides are derived from a polypeptide that does not have significant human IgG cleavage activity. By an “engineered / modified” polypeptide, it is meant a polypeptide that has been designed and built to comprise one or more modifications relative to a polypeptide that has not been so engineered, e.g., an IdeCanis comprising the amino acid sequence set forth in SEQ ID NO: 2. IdeCanis does not have significant human immunoglobulin cleavage activity, and in particular human IgG cysteine protease activity. In some embodiments, polypeptides of the present disclosure are those for which the amino acid sequence varies from that set forth in SEQ ID NO:2 (IdeCanis), but which have a human IgG cleavage activity and hence can serve as replacement for a polypeptide comprising an amino acid sequence set forth in SEQ ID NO: 1 (IdeS). Polypeptides provided herein are mutants of IdeCanis that display human IgG cysteine protease activity. In some embodiments, polypeptides of the present disclosure display human immunoglobulin cysteine protease activity, and in particular human IgG cysteine protease activity. The polypeptides disclosed herein may cleave a human IgG in the hinge region of the heavy chain. The cleavage may result in production of Fc and Fab fragments of the human IgG. In some embodiments, human IgG antibody is IgG1, IgG2, IgG3 and / or IgG4. In some embodiments, polypeptides of the present disclosure comprise an amino acid sequence having 80% or less than 80% sequence identity to amino acid sequence of SEQ ID NO:1. In some embodiments, polypeptides of the present disclosure having human IgG protease activity comprise an amino acid sequence having at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO:2. In certain cases, the polypeptides having human IgG protease activity comprise an amino acid sequence having at least 90% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO:2. In certain embodiments, the polypeptides having human IgG protease activity comprise an amino acid sequence having 90% to 98%, 91% Atty Docket No.: NHWK-003WO to 98%, 92% to 98%, 93% to 98%, 94% to 98%, 95% to 98%, 96% to 98%, or 97% to 98% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO:2. In certain embodiments, the polypeptides having human IgG protease activity comprise an amino acid sequence having no more than 98.5% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO:2. As used herein, the term “IdeS”, also known as Mac, refers to a cysteine protease secreted by the human pathogen Streptococcus pyogenes. IdeS / Mac cleaves the hinge region of human IgG with high specificity, thereby interferes with phagocytic killing (Lei et al., 2001, 2002; Von Pawel-Rammingen et al., 2002; Von Pawel-Rammingen & Björck, 2003). Herein, IdeS is a protease enzyme comprising the amino acid sequence set forth in SEQ ID NO:1. In some embodiments, polypeptides of the present disclosure having human IgG protease activity comprise an amino acid sequence having 80% or less sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO:1. For example, polypeptides of the present disclosure having human IgG protease activity comprise an amino acid sequence having at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, or 80% sequence identity the amino acid sequence of IdeS as set forth in SEQ ID NO:1. In certain embodiments, polypeptides of the present disclosure having human IgG protease activity comprise an amino acid sequence having no more than 74% to 80% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO:1. In some aspect, a polypeptide of the present disclosure having human IgG protease activity comprises an amino acid sequence having at least 85% identity to the amino acid sequences of SEQ ID NO:2 and comprises the amino acids: (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and / or (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide has at least 90% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO:2. In other embodiments, the amino acid sequence of the polypeptide has no more than 94 % to 98 % sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In other embodiments, the amino acid sequence of the Atty Docket No.: NHWK-003WO polypeptide has no more than 98.5 % sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide has no more than 75% to 81% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO:1. In some embodiments, the amino acid sequence of the polypeptide has no more than 81% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO:1. In some embodiments, the polypeptide cleaves Fc hinge of the human IgG antibody. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises an amino acid sequence having at least 85% identity to the amino acid sequences of SEQ ID NO:2 and comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has no more than 97.6% to 98.6% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has 98.1% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has no more than 76.0% to 77.0% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has 76.5% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least Atty Docket No.: NHWK-003WO 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 4. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and has the amino acid sequence set forth in SEQ ID NO: 4. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has no more than 97.6% to 98.6% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has 98.1% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has no more than 76.0% to 77.0% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has 76.5% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. Atty Docket No.: NHWK-003WO In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 5. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has the amino acid sequence set forth in SEQ ID NO: 5. In some embodiments, the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and cleaves Fc hinge of the human IgG3 and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has no more than 96.0% to 97.0% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at Atty Docket No.: NHWK-003WO position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has 96.5% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has no more than 77.6% to 78.6% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has 78.1% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 6. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has the amino acid sequence set forth in SEQ ID NO: 6. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232 and; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, Atty Docket No.: NHWK-003WO V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG1, IgG3 and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG3 and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has no more than 95.6% to 96.6% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has 96.1% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has no more than 77.9% to 78.9% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G Atty Docket No.: NHWK-003WO at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has 78.4% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 7. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and has the amino acid sequence set forth in SEQ ID NO: 7. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acids (iii) Y at position 134, T at position 137, Atty Docket No.: NHWK-003WO K at position 138, H at position 139, L at position 140, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has no more than 94.0% to 95.0% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has 94.5% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has no more than 79.5% to 80.5% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has 80.0% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at Atty Docket No.: NHWK-003WO position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 9. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and has the amino acid sequence set forth in SEQ ID NO: 9. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid Atty Docket No.: NHWK-003WO sequence of SEQ ID NO:2; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has no more than 96.0% to 97.0% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 96.5% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has no more than 76.9% to 77.9% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 77.4% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In certain embodiments, the amino acid Atty Docket No.: NHWK-003WO sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has Atty Docket No.: NHWK-003WO no more than 94.0% to 95.0% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 94.5% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has no more than 78.9% to 79.9% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 79.4% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position Atty Docket No.: NHWK-003WO 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has no more than 94.3% to 95.3% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position Atty Docket No.: NHWK-003WO 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 94.8% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has no more than 78.5% to 79.5% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has 79.0% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and has the amino acid sequence set forth in SEQ ID NO: 13. Atty Docket No.: NHWK-003WO In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, and cleaves Fc hinge of the human IgG3 and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has no more than 97.2% to 98.2% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has 97.7% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. Atty Docket No.: NHWK-003WO In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has no more than 76.3% to 77.3% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has 76.8% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 15. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and has the amino acid sequence set forth in SEQ ID NO: 15. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at Atty Docket No.: NHWK-003WO position 229, R at position 230, N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has no more than 95.6% to 96.6% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has 96.1% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has no more than 77.9% to 78.9% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has 78.4% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least Atty Docket No.: NHWK-003WO 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 16. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and has the amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232 based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289 based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 307 based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position Atty Docket No.: NHWK-003WO 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has no more than 95.3% to 96.3% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has 95.8% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has no more than 78.2% to 79.2% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has 78.7% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 17. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at Atty Docket No.: NHWK-003WO position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and has the amino acid sequence set forth in SEQ ID NO: 17. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has no more than 93.7% to 94.7% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position Atty Docket No.: NHWK-003WO 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has 94.2% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has no more than 79.2% to 80.2% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has 79.7% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:18. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids Atty Docket No.: NHWK-003WO (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and has the amino acid sequence set forth in SEQ ID NO:18. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 187, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position Atty Docket No.: NHWK-003WO 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 95.6% to 96.6% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has 96.1% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 77.2% to 78.2% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has 77.7% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 23. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position Atty Docket No.: NHWK-003WO 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and has the amino acid sequence set forth in SEQ ID NO: 23. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 187, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 95.3% to 96.3% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and Atty Docket No.: NHWK-003WO I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has 95.8% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 77.6% to 78.6% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has 78.1% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 24. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and has the amino acid sequence set forth in SEQ ID NO: 24. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at Atty Docket No.: NHWK-003WO position 187, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In some aspects, a polypeptide of the present disclosure having human IgG protease activity comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; the amino acid N at position 307, based on the numbering of the amino acid sequence of SEQ ID NO:2; and the amino acid N at position 187, based on the numbering of the amino acid sequence of SEQ ID NO:2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 97.2% to 98.2% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and has 97.7% sequence identity to the amino acid sequence of IdeCanis as set forth in SEQ ID NO: 2. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and has no more than 75.6% to 76.6% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In certain cases, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino Atty Docket No.: NHWK-003WO acid N at position 187, and has 76.1% sequence identity to the amino acid sequence of IdeS as set forth in SEQ ID NO: 1. In some embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and has at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 25. In certain embodiments, the amino acid sequence of the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and has the amino acid sequence set forth in SEQ ID NO: 25. In some embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG antibody. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. In certain embodiments, the polypeptide comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, and cleaves Fc hinge of the human IgG1, IgG3, and IgG4. In some embodiments, human IgG cleavage activity of the polypeptides of the present disclosure may be measured using any suitable method. In some examples, polypeptides of the present disclosure may cleave at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or more of a human IgG when incubated with the human IgG under suitable conditions. Suitable conditions may include conditions inside a human body or in laboratory environment. In certain embodiments, the cleavage activity of a polypeptide of the present disclosure may be assayed in a buffer at a physiological pH at room temperature or at 37C. Atty Docket No.: NHWK-003WO In some embodiments, polypeptides of the present disclosure show significantly reduced binding to anti-IdeS pre-existing antibodies in pooled human serum as compared to the binding by IdeS. For example, the binding of polypeptides of the present disclosure to anti-IdeS pre- existing antibodies in pooled human serum is reduced by at least 30%, at least 40%, at least 50%, at least 60%, or more as compared to the binding of IdeS to the anti-IdeS pre-existing antibodies in pooled human serum. In some embodiments, polypeptides of interest do not show detectable binding to anti-IdeS pre-existing antibodies. In some embodiments, the anti-IdeS pre-existing antibodies are antibodies present in a human subject previously exposed to IdeS, e.g., due to an infection with S. pyogenes and / or due to treatment with IdeS. Any convenient methods may be deployed to modify a polypeptide to become an engineered or mutated polypeptide of the present disclosure. In some embodiments, other than the recited amino acid(s) present at a specified position(s), the polypeptides provided herein may have an amino acid sequence that is at least 85% identical to the amino acid sequence of SEQ ID NO:2 and includes one or more of the loop M1, loop M3, and loop M4 as set forth in SEQ ID NO:2 with one or more of the amino acid substitution(s) disclosed herein. In some embodiments, the polypeptide may further comprise one or more of the active sites K55, C65, H233, D255, and D257. Unless specified otherwise, numbering of the amino acid residues of the polypeptides described herein is based on the numbering of the amino acid residues in SEQ ID NO:2. In some embodiments, the polypeptides described herein may include modifications that improve yield, half-life, activity, and / or utility, etc. In some embodiments, the polypeptides may include one or more non-naturally occurring amino acids, for example to increase stability. When the polypeptides are produced by synthetic means, such amino acids may be introduced during production. The polypeptides may also be modified following either synthetic or recombinant production. Polypeptides may also be produced using one or more D-amino acids. In such cases the amino acids will be linked in reverse sequence in the C to N orientation. One or more side chain modifications may be made to the side chains of the amino acids of the polypeptides. Modified side chains may serve as reactive moieties for, e.g., conjugation to molecules, such as, small molecules. Atty Docket No.: NHWK-003WO In some examples, the polypeptides may be conjugated to small molecules, e.g., small molecule drugs, peptide drugs, toxins (e.g., cytotoxins), and the like. The small molecule(s) may be conjugated to the polypeptide directly or via a linker. In some embodiments, the polypeptide may include an engineered site (e.g., an amino acid sequence) to which the small molecule(s) is attached. “Small molecule drug” as used herein refers to a compound, e.g., an organic compound, which exhibits a pharmaceutical activity of interest and which is generally of a molecular weight of no greater than about 800 Da, or no greater than 2000 Da, but can encompass molecules of up to 5kDa and can be as large as about 10 kDa. A small inorganic molecule refers to a molecule containing no carbon atoms, while a small organic molecule refers to a compound containing at least one carbon atom. In some embodiments, the polypeptides may be covalently modified, e.g., post- translationally. For example, they may be glycosylated, phosphorylated or PEGylated. In some embodiments, the polypeptides may be modified to assist with their production. For example, where a polypeptide is produced by recombinant expression in a bacterial host cell, the sequence of the polypeptide may include a methionine (M) residue at the N terminus to improve expression. In some embodiments, the polypeptides may be fused to a tag for ease of purification. Such a tag may be a biotin tag, a poly-histidine tag. Typically, the amino acid coding sequence of the histidine or biotin tag is included at the gene level and the polypeptide is expressed recombinantly in E. coli. The histidine or biotin tag is typically present at either end of the polypeptide. The tag may be separated from the polypeptide sequence via any suitable linker sequence, such as 3, 4 or 5 glycine residues or Gly / Ser residues or joined indirectly to the polypeptide sequence. The histidine tag typically consists of six histidine residues, although it can be longer than this, typically up to 7, 8, 9, 10 or 20 amino acids or shorter. Also disclosed herein are fusion proteins comprising the polypeptides provided herein. The polypeptide may be fused to a domain to increase stability and / or half-life. In some examples, the polypeptide may be fused to a VHH or Fc domain. In some examples, the polypeptide may be fused to albumin or maltose binding protein. Atty Docket No.: NHWK-003WO The polypeptides disclosed herein may be monomeric or multimeric. Multimeric forms may include each 2, 3, or 4 of the polypeptides. For example, the polypeptides may be fused in a row – the C-terminus of a polypeptide conjugated to the N-terminus of the second polypeptide and so on. In multimeric forms, the multiple copies of the polypeptide may be identical or may be different polypeptides. The compositions disclosed herein may include the polypeptides that are in monomeric form, multimeric form or a mixture of both forms. 2. Pharmaceutical Compositions In some aspects, the present disclosure provides a pharmaceutical composition comprising a polypeptide of the present disclosure and a pharmaceutically acceptable carrier, diluent or excipient. The polypeptide of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. In methods of treating a human subject with a polypeptide having human IgG protease activity of the present disclosure, the human subject will typically be administered a pharmaceutical composition comprising the polypeptide having human IgG protease activity of the present disclosure. By a pharmaceutical composition, it is meant a polypeptide of the present disclosure that has been formulated with a pharmaceutically acceptable carrier. The pharmaceutical compositions of the disclosure are formulated at and administered at a therapeutically effective dosage, e.g., a dosage sufficient to provide treatment for the disease states. While all typical routes of administration are contemplated (e.g., oral, topical, transdermal, injection (intramuscular, intravenous, or intra-arterial)), it is presently preferred to provide liquid dosage forms suitable for injection. Generally, depending on the intended mode of administration, the pharmaceutically acceptable composition will contain about 0.1% to 95%, preferably about 0.5% to 50%, by weight of the subject polypeptide of the present disclosure, the remainder being suitable pharmaceutical excipients, carriers, etc. Dosage forms or compositions containing active ingredient in the range of 0.005% to 95% with the balance made up from non-toxic carrier can be prepared. Atty Docket No.: NHWK-003WO The subject pharmaceutical compositions can be administered either alone or in combination with other pharmaceutical agents. These compositions can include other medicinal agents, pharmaceutical agents, carriers, and the like, including, but not limited to other active agents that can act as immune-modulating agents and more specifically can have inhibitory effects on B-cells, including anti-folates, immune suppressants, cytostatics, mitotic inhibitors, and anti-metabolites, or combinations thereof. Liquid pharmaceutically administrable compositions can, for example, be prepared by dissolving, dispersing, etc. an active composition of the disclosure (e.g., a lyophilized powder) and optional pharmaceutical adjuvants in a carrier, such as, for example, water (water for injection), saline, aqueous dextrose, glycerol, glycols, ethanol or the like (excluding galactoses), to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered can also contain minor amounts of nontoxic auxiliary substances such as wetting agents, emulsifying agents, stabilizing agents, solubilizing agents, pH buffering agents and the like, for example, sodium acetate, sodium citrate, cyclodextrine derivatives, sorbitan monolaurate, triethanolamine acetate and triethanolamine oleate, etc., osmolytes, amino acids, sugars and carbohydrates, proteins and polymers, salts, surfactants, chelators and antioxidants, preservatives, and specific ligands. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington: The Science and Practice of Pharmacy, Pharmaceutical Press, 22nd Edition, 2012. The composition or formulation to be administered will, in any event, contain a quantity of the active compound in an amount effective to treat the symptoms of the subject being treated. 3. A nucleic acid encoding a polypeptide of the present disclosure The present disclosure provides a nucleic acid encoding a polypeptide of the present disclosure. The polypeptide of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. In some embodiments, the nucleic acid may be fused to a sequence encoding a tag. In some embodiments, the tag is a protein tag that facilitates purification or tracking of the polypeptide. Such protein tags include His tag, a hemagglutinin tag, a Fc region (derived from an Ig from a human), a Myc tag, etc. Atty Docket No.: NHWK-003WO In some embodiments, the nucleic acid may be DNA or RNA, which may be single stranded or double stranded. In some embodiments, the nucleic acid have naturally occurring nucleotides and backbone or modified nucleotides and / or backbone. Also contemplated herein are compositions, e.g., pharmaceutical compositions, comprising such nucleic acids. 4. A recombinant expression vector comprising a nucleic acid of the present disclosure In some aspects, the present disclosure provides a recombinant expression vector comprising a nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure. The polypeptide of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. The vectors may be for example, plasmid, virus or phage vectors provided with a origin of replication, optionally a promoter for the expression of the polypeptide and optionally a regulator of the promoter. The vectors may contain one or more selectable marker genes, for example an ampicillin resistance gene in the case of a bacterial plasmid or a resistance gene for a fungal vector. In some aspects, the vector may be designed for delivering a nucleic acid encoding a polypeptide of the present disclosure to a cell for, example, therapeutic purposes. Some examples of suitable viral vectors include herpes simplex viral vectors and retroviruses, including lentiviruses, adenoviruses, adeno-associated viruses and HPV viruses. Gene transfer techniques using these viruses are known to those skilled in the art. Retrovirus vectors for example may be used to stably integrate the polynucleotide giving rise to the polynucleotide into the host genome. Replication-defective adenovirus vectors by contrast remain episomal and therefore allow transient expression. Vectors may be used in vitro, for example for the production of DNA or RNA or used to transfect or transform a host cell, for example, a mammalian host cell. The vectors may also be adapted to be used in vivo, for example in a method of gene therapy or nucleic acid immunization. In some embodiments, the vector is an expression vector comprising a nucleic acid sequence that encodes a polypeptide of the present disclosure. Such expression vectors are Atty Docket No.: NHWK-003WO routinely constructed in the art of molecular biology and may for example involve the use of plasmid DNA and appropriate initiators, promoters, enhancers and other elements, which may be necessary, and which are positioned in the correct orientation, in order to allow for protein expression. Other suitable vectors would be apparent to persons skilled in the art. Expression vectors may be transformed into a suitable host cell to provide for expression of a polypeptide of the present disclosure. The host cell, transformed or transfected with an expression vector is cultivated under conditions to allow for expression of the polypeptide, and the expressed polypeptide is recovered by, e.g., purification. Host cells compatible with the vector can be chosen and may be a microorganism, e.g., bacterial cells. Host cells may also be cells of a non-human animal, plant cells, primary human cells, human cell lines, etc. 5. A host cell comprising a nucleic acid or a recombinant expression vector of the present disclosure In some aspects, the present disclosure provides a host cell, e.g., genetically modified host cells, comprising the nucleic acid or the recombinant expression vector encoding a polypeptide of the present disclosure. The polypeptide of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. In some embodiments, the host cell can be an isolated cell, e.g., a cell in in vitro culture. In other embodiments, the host cell is useful for producing a recombinant adeno-associated virus (rAAV) vectors. In some embodiments, the host cell is stably genetically modified with the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure. In other embodiments, the host cell is transiently genetically modified with the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure. In some embodiments, the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure is introduced stably or transiently into a host cell, using established techniques, including, but not limited to, electroporation, calcium phosphate precipitation, liposome-mediated transfection, and the like. For stable transformation, a subject nucleic acid will generally further include a selectable marker, e.g., any of several well-known selectable markers such as neomycin resistance, and the like. Atty Docket No.: NHWK-003WO In some embodiments, the host cell is generated by introducing the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure into any of a variety of cells, e.g., mammalian cells, including, e.g., murine cells, and primate cells (e.g., human cells). Suitable mammalian cells include, but are not limited to, primary cells and cell lines, where suitable cell lines include, but are not limited to, 293 cells, COS cells, HeLa cells, Vero cells, 3T3 mouse fibroblasts, C3H10T1 / 2 fibroblasts, CHO cells, and the like. Non-limiting examples of suitable host cells include, e.g., HeLa cells (e.g., American Type Culture Collection (ATCC) No. CCL- 2), CHO cells (e.g., ATCC Nos. CRL9618, CCL61, CRL9096), 293 cells (e.g., ATCC No. CRL-1573), Vero cells, NIH 3T3 cells (e.g., ATCC No. CRL-1658), Huh-7 cells, BHK cells (e.g., ATCC No. CCL10), PC12 cells (ATCC No. CRL1721), COS cells, COS-7 cells (ATCC No. CRL1651), RAT1 cells, mouse L cells (ATCC No. CCLI.3), human embryonic kidney (HEK) cells (ATCC No. CRL1573), HLHepG2 cells, and the like. A subject host cell can also be made using a baculovirus to infect insect cells such as Sf9 cells, which produce AAV (see, e.g., U.S. Patent No. 7,271,002; US patent application 12 / 297,958). In some embodiments, the host cell further comprises an rAAV vector. An rAAV virion can be generated using the host cell. Methods of generating an rAAV virion are described in, e.g., U.S. Patent Publication No.2005 / 0053922 and U.S. Patent Publication No.2009 / 0202490. 6. Methods for using a polypeptide of the present disclosure as a therapeutic or for generating antibody fragments (1) Methods for treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof In some aspects, the present disclosure provides a method of treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof. In certain aspects, the present disclosure provides a method for pre-treating highly sensitized patients to decrease transplant rejection response prior to receiving a transplant, such as, a kidney transplant. In some embodiments, a disease mediated by IgG antibodies may be an autoimmune disease. For example, the autoimmune disease or disorder is Pemphigus vulgaris, celiac disease, primary biliary cholangitis, membranous nephropathy, rheumatoid arthritis, Systemic lupus Atty Docket No.: NHWK-003WO erythematosus rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, psoriasis, hidradenitis suppurativa, uveitis, Idiopathic thrombocytopenic purpura (ITP) or juvenile idiopathic arthritis. In some embodiments, the auto-immune disease is primarily driven by IgG1 and IgG3, such as, Sjogren syndrome, systemic sclerosis, systemic lupus erythematosus, primary biliary cirrhosis, membranous nephritis, and myasthenia gravis. In some embodiments, the auto-immune disease is primarily driven by pathogenic IgG4 autoantibodies, such as, Musk myasthenia gravis, pemphigus foliaceus, pemphigus vulgaris, and thrombotic thrombocytopenic purpura. In some embodiments, the method comprises administering to the subject a therapeutically effective amount of a polypeptide having human IgG protease activity of the present disclosure, wherein the polypeptide has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease. The polypeptides of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. In other aspects, the present disclosure provides a method of treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a pharmaceutical composition comprising a polypeptide having human IgG protease activity of the present disclosure, wherein the polypeptide has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease. The pharmaceutical composition of the present disclosure is described in “2. Pharmaceutical Compositions”. In still other aspects, the present disclosure provides a method of treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure, or an expression vector comprising the nucleic acid, wherein the polypeptide has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease. The nucleic acid of the present disclosure is described in “3. A nucleic acid encoding a polypeptide of the present disclosure”. The recombinant expression vector of the present disclosure is described in “4. A recombinant expression vector comprising a nucleic acid of the present disclosure”. Atty Docket No.: NHWK-003WO In still other aspects, the present disclosure provides a method of treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a host cell comprising the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure or an expression vector comprising the nucleic acid, wherein the polypeptide has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease. The host cell of the present disclosure is described in “5. A host cell comprising a nucleic acid or a recombinant expression vector of the present disclosure”. In still other aspects, the present disclosure provides a method of treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a viral vector (e.g. AAV or lentivirus) comprising the nucleic acid encoding a polypeptide having human IgG protease activity of the present disclosure, wherein the polypeptide has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease. In some embodiments, treatment can be administered for a single day or a period of days, and can be repeated at intervals of several days, one or several weeks, or one or several months. Administration can be as a single dose (e.g., as a bolus) or as an initial bolus followed by continuous infusion of the remaining portion of a complete dose over time, e.g., 1 to 7 days. The amount of active compound administered will, of course, be dependent on any or all of the following: the subject and disease state being treated, the severity of the affliction, the manner and schedule of administration and the judgment of the prescribing physician. It will also be appreciated that amounts administered will depend upon the molecular weight of the protease. In some aspects, the present disclosure provides a method for treating a human subject previously exposed to IdeS by, e.g., an infection by S. pyogenes and / or treatment with IdeS. In some aspects, the human subject may have anti-IdeS pre-existing antibodies due to the prior exposure to IdeS. In some aspects, the human subject is not a suitable candidate for receiving IdeS therapy due to the presence of anti-IdeS antibodies in the subject. In some aspects, the human subject may have a disease mediated by IgG antibodies, such as, an autoimmune disease and may have pre-existing anti-IdeS antibodies. Atty Docket No.: NHWK-003WO (2) Methods for treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies The present invention provides a method of treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies. The method comprises contacting the blood with a polypeptide of the present disclosure. The polypeptides of the present disclosure may be as described in section 1, “Polypeptides having human IgG protease activity”. In some embodiments, the blood is returned to the patient after contacting it with the polypeptide. In some embodiments, the disease mediated by IgG antibodies is an autoimmune disease. For example, the autoimmune disease or disorder is selected from the group consisting of Pemphigus vulgaris, celiac disease, primary biliary cholangitis, membranous nephropathy, rheumatoid arthritis, Systemic lupus erythematosus rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, psoriasis, hidradenitis suppurativa, uveitis, and juvenile idiopathic arthritis. In some embodiments, the auto-immune disease is primarily driven by IgG1 and IgG3, such as, Sjogren syndrome, systemic sclerosis, systemic lupus erythematosus, primary biliary cirrhosis, membranous nephritis, and myasthenia gravis. In some embodiments, the auto-immune disease is primarily driven by pathogenic IgG4 autoantibodies, such as, Musk myasthenia gravis, pemphigus foliaceus, pemphigus vulgaris, and thrombotic thrombocytopenic purpura. In some embodiments, the polypeptide of the present disclosure may thus be used for extracorporeal treatment of blood or one or more components of blood, such as plasma or serum. The ex vivo method described herein may be practiced on blood that has previously been removed from the body of a patient or on plasma or serum prepared from the blood. The blood or blood product may optionally be returned to the patient after being contacted with a polypeptide of the present disclosure. (3) Methods of preparing a fragment of human IgG antibody In some aspects, the present disclosure provides a method of preparing a fragment of human IgG antibody, comprising: contacting the human IgG antibody with a polypeptide provided herein. The polypeptide may cleaves the IgG in the hinge region of the heavy chain Atty Docket No.: NHWK-003WO resulting in production of Fc and Fab fragments of the IgG. As such, the polypeptide cleaves Fc hinge of the IgG antibody to generate a Fab fragment and a Fc fragment. In some embodiments, the method further comprises isolating the Fab or Fc fragment of the human IgG antibody. The human IgG antibody is human IgG1, IgG2, IgG3 or IgG4. In some embodiments, the method comprises contacting the human IgG antibody with a polypeptide comprising an amino acid sequence comprising at 85% identity to the amino acid sequence of SEQ ID NO:2 and comprising the amino acids comprising the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (iii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (iv) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, wherein the polypeptide cleaves Fc hinge of the human IgG3 and IgG4; (v) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (vi) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids Y at position 134, T at position 137, K at position 138, H at Atty Docket No.: NHWK-003WO position 139, L at position 140, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (vii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (viii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (ix) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (x) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (xi) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids H at position 196, D at position 197, K at position 199, N at position 200, G at position 202, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (xii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids H Atty Docket No.: NHWK-003WO at position 196, D at position 197, K at position 199, N at position 200, G at position 202, wherein the polypeptide cleaves Fc hinge of the human IgG3 and IgG4; (xiii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (xiv) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4 (xv) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (xvi) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; (xvii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4; (xviii) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; Atty Docket No.: NHWK-003WO the amino acid N at position 307; and the amino acid N at position 187, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4; or (xix) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acid N at position 307; and the amino acid N at position 187, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4. 7. Use of a polypeptide or a composition of the present disclosure In some aspects, the present disclosure provides a polypeptide or a pharmaceutical composition comprising the polypeptide for use in a method for treating a human subject in need thereof. In some embodiments, the subject may have disease mediated by IgG antibodies, e.g., an autoimmune disease. The subject may have previously been exposed to IdeS, e.g., an infection by S. pyogenes and / or previous treatment with IdeS. The polypeptides of the present disclosure is described in section 1, “Polypeptides having human IgG protease activity”. The pharmaceutical composition of the present disclosure is described in “2. Pharmaceutical Compositions”. In some aspects, the present disclosure provides a nucleic acid encoding a polypeptide of the present disclosure, a recombinant expression vector comprising the nucleic acid, a recombinant expression vector comprising the nucleic acid or the vector, or a pharmaceutical composition thereof for use in a method for treating a human subject in need thereof. The nucleic acid of the present disclosure is described in “3. A nucleic acid encoding a polypeptide of the present disclosure”. In some aspects, the present disclosure provides a host cell comprising the nucleic acid encoding a polypeptide of the present disclosure or an expression vector comprising the nucleic acid for use in a method for treating a human subject in need thereof. The host cell of the present disclosure is described in “5. A host cell comprising a nucleic acid or a recombinant expression vector of the present disclosure”. In some aspects, the present disclosure provides the polypeptide of the present disclosure for use in a method for treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, wherein the blood is returned to the patient after contacting it with the polypeptide. Atty Docket No.: NHWK-003WO Protein sequences SEQ ID Protein % % Protein Sequence NO: Name Identity Identity N H G S G G EK P L N A G EK D T S A G EK P L F G EK P L N A G EK D T N Atty Docket No.: NHWK-003WO SEGNLEAIYVTDSDSNASIGMKKYYVGVNSAGEVAVSSKKIDSEHLGAA ALGLYTLSAGQGIWHQTN G EK P L F A G EK D T S A G EK D T N A G EK P L F G EK P L D G G EK P L D G Atty Docket No.: NHWK-003WO SEQ ID M124- 79 94.8 DNIDRNQITTYSEATPSHITSIWTKGVTPPTNFIEGTDGSHAPYIANQG NO: 13 IdeCanis WYDITKTFNGKDDLLCAAATAGNMLHWWFDQNKNQIEGYLTEHPEK PD T F G EK P L N A G EK P L F G EK D T N A G EK P L F A G EK P L D G G EK P L N Atty Docket No.: NHWK-003WO SEGNLEAIYVTDSDSNASIGMKKYYVGVNSAGEVAVSSKKIDSEHLGAA ALGLYTLSAGQGIWHQTN G EK P L F G EK D T N A G EK P L F A G EK D T N A G EK P LL F A G EK P LL F Atty Docket No.: NHWK-003WO SEQ ID IdeS- 99.7 74.2 DSFSANQEIRYSEVTPYHVTSVWTKGVTPPANFTQGEDVFHAPYVAN NO: 26 C65S QGWYDITKTFNGKDDLLSGAATAGNMLHWWFDQNKDQIKRYLEEH LG S G SEQ ID Construct DNA sequence with tags Name G CT A C A A T C A T C A C A T A A A C A GT A TT G GT T T A TT A T Atty Docket No.: NHWK-003WO SEQ ID HA-M1- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 29 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A T G GT T T A TT A T A A A C A GT A TT G GT T T A TT A T

[0002] Atty Docket No.: NHWK-003WO SEQ ID HA-M3- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 31 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A TT G GT T T A TT C T A A A C A GT A TT G GT C A A G T A

[0003] Atty Docket No.: NHWK-003WO SEQ ID HA-M12- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 33 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A T G GT T T A TT A T A A A C A GT A T G GT T T A TT C T A A A C A GT A TT G GT T T A Atty Docket No.: NHWK-003WO GCGATCTACGTGACAGACTCCGATTCGAATGCAAGTATCGGGATGAAGAAGTACTACGTT GGTGTCAACTCTGCTGGTGAAGTTGCGGTCTCCTCTAAGGAAATTAAGGAAGATAATATC CT A A A C A GT A T G GT T T A TT C T A A A C A GT A TT G GT C G A G T A Atty Docket No.: NHWK-003WO SEQ ID HA-M234- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 38 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A TT G GT C G A G A A A A A C A GT A T G GT C G A G T A

[0004] Atty Docket No.: NHWK-003WO SEQ ID HA-M23- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 40 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A TT G GT T T A TT C T A A A C A GT A TT G GT T T A TT A T

[0005] Atty Docket No.: NHWK-003WO SEQ ID HA-M12- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 42 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A T G GT T T A TT A T A A A C A GT A TT G GT C G A G A A A A A C A GT A TT G GT T T A Atty Docket No.: NHWK-003WO GCGATCTACGTGACAGACTCCGATTCGAATGCAAGTATCGGGATGAAGAAGTACTACGTT GGTGTCAACTCTGCTGGTGAAGTTGCGGTCTCCTCTAAGAAAATTGACAGCGAACACTTA CT A A A C A GT A TT G GT T T A TT A T A A A C A GT A T G GT T T A TT A T Atty Docket No.: NHWK-003WO SEQ ID HA-M23- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 47 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A TT G GT T T A TT C T A A A C A GT A TT G GT T T A TT A T

[0006] Atty Docket No.: NHWK-003WO SEQ ID HA-M12- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 49 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A T G T T T A TT A T A A A C A GT A TT G T T T A TT C T

[0007] Atty Docket No.: NHWK-003WO SEQ ID HA-M2- ATGTACCCATACGATGTACCAGATTATGCTGGTGGCAGCGACAATATTGACCGTAACCAA NO: 51 IdeCanis- ATTACTACCTACAGTGAAGCTACGCCCTCTCATATTACCTCCATTTGGACGAAGGGGGTTA CA C A GT A TT G T T T A TT A T G CT A TC A A T C A T C A C A T EXAMPLES EXAMPLE 1: Selecting a non-human pathogenic bacterial Mac family cysteine endopeptidase to mitigate binding of pre-existing ADA. To avoid pre-existing ADA, a Mac family cysteine endopeptidase was chosen from a bacterium which does not infect humans, but instead is a pathogen targeted at dogs, Streptococcus canis. FIG. 1 depicts the sequence alignment of IdeS, with the Mac family cysteine endopeptidase from S. canis, nicknamed IdeCanis (SEQ ID NO: 2). IdeCanis is 74.5% pairwise Atty Docket No.: NHWK-003WO identical to IdeS and possesses the same active site as IdeS (SEQ ID NO:1), a cysteine (C) at position 65, a lysine (K) at position 55, a histidine (H) at position 233, an aspartic acid (D) at position 255, and an aspartic acid at position 257. Both sequences also contain the integrin binding motif, RGD. FIG. 2 depicts the sequence alignment of canine IgG heavy chain constant regions with human heavy chain constant regions. The IdeS cleavage site annotated on FIG.2 shows that the Leucine-Glycine-Glycine-Proline (SEQ ID NO:57) motif is conserved in both human IgG1, 3, 4 and all dog IgG heavy chains, indicating that IdeCanis may also show some reactivity to human IgG proteins. EXAMPLE 2: Production of recombinant IdeS and IdeCanis proteins in E. coli. To compare IgG cleaving activity of IdeS and IdeCanis, proteins were produced in-house as described below. Materials & Methods: Expression, purification, and analysis of recombinant IdeS and IdeCanis The DNA sequence corresponding SEQ ID NO: 27 or 28 was cloned into a pET plasmid containing either an N- or C-terminal His tag. The IdeCanis construct also contained an N-terminal hemagglutinin (HA) tag for downstream assays. The constructs were transformed into BL21(DE3) chemically competent cells (Invitrogen, Cat. No. C600003) and grown overnight in Miller’s Luria Broth (LB) containing 100 μg / mL ampicillin. Overnight cultures were diluted 1:50 in fresh LB containing 100 μg / mL ampicillin and grown to OD6000.6-0.8 at 37 °C. Cultures were then induced with 1 mM Isopropyl β-d-1-thiogalactopyranoside (IPTG) for 24 hours at 30 °C. Cells were pelleted by centrifugation at 4,000 rpm for 20 min and resuspended in 40 mL of lysis buffer (20 mM Tris, 300 mM NaCl, 10 mM Imidazole, pH 8.0, and EDTA-free protease inhibitor cocktail tablet). Resuspended cells were sonicated using a Qsonica sonicator (parameters: pulse ON 1 sec, pulse OFF 2 sec, 2 min, Amplitude 40%). The lysate was clarified by centrifugation at 16,000 rpm for 20 minutes and incubated with Ni-NTA resin (Invitrogen, Cat. No. 60-0442) for 1 hour at 4 °C with end-over-end mixing. The mixture was transferred to a 25 mL column for gravity flow chromatography and washed with wash buffer (20 mM Tris, 300 mM NaCl, 20 mM Imidazole, pH 8.0). The protein was eluted with buffer containing 20 mM Tris, 300 mM NaCl, 250 mM Imidazole, pH 8.0 and buffer exchange was performed with PBS pH 7.4 using a 10 kDa Amicon Ultra-15 Atty Docket No.: NHWK-003WO Centrifugal Filter Unit. SDS-PAGE analysis was executed using Invitrogen XCell SureLock mini-Cell blot module (Invitrogen, Cat. No. EI0002), followed by staining using InstantBlue Coomassie Protein Stain (Abcam, Cat. No. ab119211). Size exclusion chromatography (SEC) was performed on an Agilent Chemstation HPLC-SEC with a Sepax-Zenix SEC-300 gel filtration column. LC-MS analysis was performed on an Agilent 6545XT AdvanceBio LC / Q-TOF TF 1.8.1 with an Agilent AdvanceBio Desalting-RP Column. Results and conclusions FIG. 3 shows (A) the analysis of SDS-PAGE and (B) the analytical SEC trace of IdeS and IdeCanis after purification with Ni-NTA capture of His-tagged proteins. Both proteins are >90% pure by SDS-PAGE. However, IdeCanis also shows less aggregation after Ni-affinity column at 95% monomer compared to IdeS at 60% monomer after Ni-affinity purification. Both proteins also had similar yields at 30 mg / L. EXAMPLE 3: Pre-existing ADA from pooled human serum displays significantly lower binding to IdeCanis in comparison to IdeS binding. To determine if pre-existing ADA binds to IdeCanis, a competitive ADA ELISA was utilized. FIG. 4A shows a representation of the competitive ADA. Briefly, plates are coated with inactive IdeS-C65S (SEQ ID NO: 26). Separately, the competitive protease or IdeS-C65S is mixed with human pooled serum. Inactive protease is used to avoid cleavage of the IgG and high NaCl concentration is used to limit low affinity ADA binders. Bound human serum is then added to the IdeS-coated plate and signal is measured by anti-human IgG-HRP protein. If the competitive protease is not recognized by the anti-IdeS antibodies then there will be a high signal produced on the IdeS-coated plate. If competitive protease is recognized by anti-IdeS antibodies, then the signal will be lower on the plate because antibodies will be depleted from serum. Materials & Methods: A competitive ADA assay to determine pre-existing ADA cross-reactivity to variant IgG C94S was coated (5 µg / mL) overnight on 96-well assay plates (Nunc Plates, Black 96-Well Immuno Plates, Thermo Scientific, Cat. No.437111) in PBS pH 7.2 overnight at 4 °C. The next day the plates were washed with PBS-T and blocked with 2% BSA, 1M NaCl in Atty Docket No.: NHWK-003WO PBS pH 7.2, and incubated at room temperature for one hour. During the blocking step, a separate plate containing test IdeCanis variants or IdeS-C65S was set up at concentrations of 0.0625 mg / mL to 0.0156 mg / mL. Optimal protease concentration was determined by titration of IdeS-C65S into serum and determination of concentration where approximately 80% of serum IgG is bound in solution and 20% can bind the IdeS immobilized on the plate. These were mixed with pooled human serum (Innovative Research, Cat. No. ISER10ML-39738) that was diluted 1:100 in assay buffer (0.1% BSA, 1M NaCl in PBS pH 7.2). The mixing plate was incubated at room temperature on a shaker for one hour. The blocking buffer was discarded after incubation and 50 uL of the mixture (in triplicates) was transferred to the assay plate and incubated at room temperature on a shaker for 1 hour. Plates were washed with PBS buffer with 0.05% Tween-20. After washing, Goat Anti-Human IgG-HRP (Southern Biotech, Cat. No. 2040-05) was added and incubated at room temperature for 1 hour. After washing the assay plates, QuantaBlu Substrate Solution (Thermo Scientific, Cat. No. 15169) was added to each well and incubated at room temperature for 15 minutes. The excitation and emission settings for the QuantaBlu Fluorogenic Peroxide Substrates are 325nm and 420nm, and the relative fluorescence units were measured using a SpectraMax plate reader. The percentage of ADA bound in solution was determined by using the formula (1 / (variant signal / IdeS signal)), where IdeS-C65S is set to 100%. Results & Conclusions: FIG.4B depicts the percent of pre-existing ADA in pooled human serum that interacts with IdeCanis. IdeCanis demonstrates a significant reduction in pre-existing ADA in comparison to IdeS, with a 65% reduction in ADA binding. The result confirms that an IgG cleaving enzyme from a non-human pathogenic bacterium, Streptococcus canis, has lower cross-reactivity with human ADA present in the serum from S. pyogenes infection. EXAMPLE 4: Wild-type IgG-cleaving cysteine protease from S. canis does not demonstrate cleavage of human IgG. To determine human IgG cleavage activity of an IgG cleaving cysteine protease from S. canis, cleavage was visualized by gel for each IgG subclass. Materials & Methods: Assessment of human IgG subclass cleavage by SDS-PAGE analysis The human IgG subclass cleavage assay was 2 µL of of IdeS Atty Docket No.: NHWK-003WO or IdeCanis variant to 10 µL of 3.33 µM of the purified antibody at a 1:1 molar equivalent. The antibody panel included human IgG1, IgG2, IgG3, IgG4, mouse IgG1, IgG2a, IgG2b, IgG3, and monkey IgG. The reaction mixture was digested at 37 °C for 20 minutes. The reaction was stopped by adding 10 µL of 3x Laemmli sample buffer containing reducing agent (Invitrogen NuPAGE Sample Reducing Agent (10X). Cat. No. NP0004), then boiled at 90 °C for 10 minutes. The sample was loaded onto a NuPAGE 4-12% Bis-Tris SDS-PAGE gel (Invitrogen, Cat. No. NP0324BOX). Gel electrophoresis was executed at 170 V for 45 minutes using Invitrogen XCell SureLock mini-Cell blot module (Invitrogen, Cat. No. EI0002), followed by staining using InstantBlue Coomassie Protein Stain (Abcam, Cat. No. ab119211). The gel was imaged using Bio-Rad ChemiDoc MP Imaging System. Results & Conclusions FIG. 5 depicts an SDS-PAGE of IgG cleavage pattern of IdeS and IdeCanis. We examined cleavage of human IgG1-4, mouse IgG1-3, and monkey IgG. As previously described in the literature, IdeS potently cleaves human IgG1-4 (lanes 5-8, FIG. 5A) and shows activity in mouse IgG3 and slight cleavage of monkey IgG. However, the IgG cleavage by IdeCanis was limited to slight activity in human IgG3 and IgG4 (lane 7, 8 FIG. 5B), where the lower cleaved heavy chain band is present, but the full-length heavy chain band is still evident. IdeCanis did not show any other IgG cleavage for any other subclass in human, mouse, or monkey IgG (lanes 5-6, 9-13, FIG. 5B). EXAMPLE 5: Engineering a Mac family cysteine endopeptidase from Streptococcus canis to cleave human IgG. IdeCanis did not have the desired human IgG cleavage activity; consequently, a protein engineering effort was initiated to develop both a pan-IgG degrader, with activity similar to IdeS, and an IgG subclass-specific degrader. IgG subclass specificity may be desirable for the safety profile of IgG degraders. Since these degraders completely cleave and eliminate all IgG function, patients may be at increased risk of developing infections during treatment. Moreover, many auto-immune diseases are primarily driven by IgG1 and IgG3, such as Sjogren syndrome, systemic sclerosis, systemic lupus erythematosus, primary biliary cirrhosis, membranous nephritis, and myasthenia gravis (Volkov et al., 2022; Zhang et al., 2015). There are also diseases that have been Atty Docket No.: NHWK-003WO associated with pathogenic IgG4 autoantibodies, such as Musk myasthenia gravis, pemphigus foliaceus, pemphigus vulgaris, and thrombotic thrombocytopenic purpura (Huijbers et al., 2018)(Koneczny, 2020). Complete degradation of all subclasses of IgGs may not be required for most auto-immune indications, and degradation of only pathogenic isotypes may be sufficient for suitable efficacy. FIG.6 depicts the crystal structure of IdeS in complex with Fc domain of IgG1 (PDB 8A47) (Sudol et al., 2022). An overlay of the IdeCanis sequence (SEQ ID NO: 2) with the structure did not show any obvious sequence deviations that would cause IdeCanis to have detrimental binding or cleavage of human IgGs. IdeS does appear to have a large binding interface with the IgG, although the interaction with the upper hinge and Fab region is not captured on the Fc structure. To gain back human IgG cleavage activity, loops on the interface of the IdeS:IgG complex were identified which could be mutated in the IdeCanis sequence. Four loops were identified and labeled M1-4 on the sequence alignment FIG. 1 and backbone spheres on the crystal structure in FIG.4. Loop M1 is positioned below the IgG hinge region. Loop M2 is in direct contact with the hinge region. Loop M3 does not appear to have any contacts with the IgG but was hypothesized to contact IgG Fab region above the hinge. Loop M4 is located above the IgG hinge and may also play a role in specificity with additional contacts above the hinge. From IdeCanis, Loop M1 has the amino acid sequence: ARRRGVF (SEQ ID NO:53). Loop M2 has the amino acid sequence: AISHTYNNIGIS (SEQ ID NO:56). Loop M3 has the amino acid sequence: KIDSEHL (SEQ ID NO:54). Loop M4 has the amino acid sequence: RYNLRTKTI (SEQ ID NO:55). EXAMPLE 6: Recombinant production of variant IdeCanis proteins. The new IdeCanis variants were produced in E. coli for made single mutations and combinations of loops to increase the activity. Table 1 lists the mutations for each construct that was tested: TABLE 1 IdeCanis Variant Modification Sites g Atty Docket No.: NHWK-003WO M2-IdeCanis A221G, I222L, N227A, I229V, G230R, S232N SEQ ID NO: 4 Atty Docket No.: NHWK-003WO C65S, A221G, I222L, N227A, I229V, G230R, M23-IdeCanis-C65S S232N, K283E, D285K, S286E, E287D, H288N, SEQ ID NO: 22 onsrucs were expresse , pur e , an anayze as escr e a oven e me o s section of Example 2. Results and conclusions TABLE 2. summarizes the crude yields and purity of the IdeCanis variants. Production of IdeCanis Variants Yi l E ) Atty Docket No.: NHWK-003WO SEQ ID NO: 48 HA-IdeCanis-C65S-His6 9 80.26 SEQ ID NO: 49 HA-M12-IdeCanis-D187N-His6 122 90 IdeCanis. However, there was an increase in aggregate species to 33% compared to 5% for IdeCanis present after Ni affinity purification. The M2 loop mutations maintained similar monomeric quality to IdeCanis, but more than doubled the crude yield. The M3 loop addition did increase yield, but there was also an increase in aggregation to 36%. Addition of M1 loop to any other loop also increased production at least 3.5-fold, as shown in M12-, M13-, M123-, and M124-IdeCanis constructs. Generally, the addition of M2 loop to other loops increased monomeric purity of the expressed protein, demonstrated by M12-, M23-, M24-, M234-, and M124-IdeCanis proteins. Interestingly, M123-IdeCanis did show significant aggregation at ~30% aggregate. Overall, the proteins with the best combined expression and purity profile are M2-, M12-, M23-, and M24-IdeCanis. EXAMPLE 7: SDS-PAGE analysis of IgG cleavage activity To determine human IgG cleavage activity of an IgG cleaving cysteine protease variants from S. canis, cleavage was visualized by gel for each IgG subclass. See Example 4 for detailed SDS-PAGE protocol. The cleavage profiles were categorized based on the amount of cleavage observed, which was either none, partial, or maximum. A rating of -, +, or +++ was respectively assigned to each category. Results & Conclusions FIG. 7 shows the visualization of the SDS-PAGE gels for a subset of IdeCanis variants. TABLE 3 summarizes the results from the SDS-PAGE analysis for all IdeCanis variants tested for human IgG cleavage. TABLE 3. IgG activity assessment with SDS-PAGE Protein Name ID hum-IgG1 hum-IgG2 hum-IgG3 hum-IgG4 Atty Docket No.: NHWK-003WO M2-IdeCanis SEQ ID NO: 4+++ - +++ +++M3-IdeCanis SEQ ID NO: 5 + + +++ +++ +++ C l t l f HC ith f ll l th b d b d Loop mutations, M1 (SEQ ID NO: 3) did not show any activity for any IgG subclass. Single loop variants of M2 (SEQ ID NO: 4) and M3 (SEQ ID NO: 5) do show increased activity for human IgGs. M2 displays complete cleavage for IgG1, 3, 4 while leaving IgG2 heavy chain intact. IgG2 compromises 32% of all IgG and is responsible for defending against bacterial and viral pathogens, an IgG2-sparing could limit infection risk associated with an IgG degrading enzyme. M3 shows limited cleavage of IgG1 and IgG2, but complete cleavage of IgG3 and IgG4. The M4 loop substitution (SEQ ID NO: 10) only resulted in slight cleavage of IgG3 and IgG4, a similar profile to the wild-type IdeCanis. Combinations of the above loops were also tested for human IgG cleavage. Interestingly, the addition of M1 mutant, which did not show cleavage of any of the IgG subclasses, to the M2 Atty Docket No.: NHWK-003WO loop (termed M12-IdeCanis, SEQ ID NO: 6) created an IgG4-specific enzyme that showed very little cleavage of the other IgG subclasses. The combination of M2 mutations with M3 mutations (termed M23-IdeCanis, SEQ ID NO: 7) resulted in a protease that has activity for all IgG subclasses. M23-IdeCanis did still show some undigested heavy chain, so it appears to have a lower potency than IdeS, but there is evidence of digestion. M24-IdeCanis (SEQ ID NO: 11) looked very similar to M24, but with less cleavage for IgG2. M13-IdeCanis (SEQ ID NO: 8) was even less active than the parental IdeCanis protein. Combinations of 3 loop variants, M1, M2, M3 (termed M123-IdeCanis, SEQ ID NO: 9) showed slightly less cleavage of IgG1 than M23-IdeCanis. M2, M3, M4 loops(termed M234- IdeCanis, SEQ ID NO: 12), had a similar cleavage profile to M23-IdeCanis, but displayed slightly less cleavage of IgG2. The final triple variant evaluated was M1, M2, M4 (termed M124-IdeCanis, SEQ ID NO: 13), which had only slight activity on IgG1, IgG3, IgG4. The addition of a point mutation to the N-terminus, H307N, or mutation of the integrin binding site, RGD, with D187N, did not change the cleavage profile of the IdeCanis variants. While the visualization of cleavage with SDS-PAGE allows for a quick assessment of activity, to better understand IgG-cleavage activity, a potency ELISA was utilized to compare activity with IdeS. EXAMPLE 8: IgG subclass cleavage potency ELISA To determine potency relative to IdeS, an ELISA was developed to quantify IgG cleavage. The assay was employed for all human IgG subclasses. For IgG1, IgG3, and IgG4, TNFα was used to capture Adalimumab or an Adalimumab variable domain fused to IgG3 or IgG4 constant domains. For IgG2 capture, IL6R was used to capture Satralizumab. After capture, wells were incubated with IgG protease. After washing, Fc was detected using an anti-Fc antibody. As cleavage increases, anti-Fc signal decreases due to the loss of Fc. The signals are then graphed against IdeS concentration in each well and fit to an EC50 curve. The resulting EC50 values are compared to the wild-type IdeS (SEQ ID NO: 1) EC50 by a “fold-change” value, which is calculated by dividing the novel IdeS construct EC50 value by the wild-type EC50 value. Materials & Methods: Expression, purification, and analysis of recombinant reagent antibodies. For antibody expression of Adalimumab-IgG1, Adalimumab-IgG3, Adalimumab-IgG4, and Satralizumab, the ExpiFectamine 293 Transfection kit (Life Technologies, Cat. No. A14524) was Atty Docket No.: NHWK-003WO used to transfect suspension Expi293F cells (Life Technologies, Cat. No. A14527) with heavy chain and light chain plasmids on separate pTT5 vectors at a 1:1 ratio. Supernatant was harvested 3-6 days post-transfection by centrifugation and filtered using 0.2 μm PES vacuum sterile single-use filter unit (Thermo Scientific, Cat. No.5670020). Purification was performed with MabSelect Sure resin (Cytiva / GE, Cat. No. 17-5438-03) for all antibodies except the Adalimumab-IgG3, which was captured using Pierce Protein G agarose (Thermo Scientific, Cat. No. 23099). Briefly, each column was equilibrated with PBS pH 7.2 and loaded with culture supernatant. After the loading step, the column was washed with PBS pH 7.2 and eluted with 10 mL IgG Elution buffer (Thermo Scientific, Cat. No.21004). The pH of the elution pool was adjusted with 1 mL 1 M Sodium Phosphate pH 8.0 for each 10 mL elution pool. Buffer exchange was performed with PBS pH 7.2 using a 30 kDa Amicon Ultra-15 Centrifugal Filter Unit. Finally, preparative size exclusion chromatography (prepSEC) was performed at 4 °C using either Superdex 200 Increase 10 / 300 GL or HiLoad 16 / 600 Superdex 200 pg at a flow rate of 0.75 mL / min, with PBS pH 7.2. For the antigens, TNFα and IL6R, the corresponding DNA sequence was cloned into a pTT5 vector containing a C-terminal His6 sequence and an N-terminal secretion sequence. Again, the ExpiFectamine 293 Transfection kit (Life Technologies, Cat. No. A14524) was used to transfect suspension Expi293F cells (Life Technologies, Cat. No. A14527). Media was harvested 3-6 days post-transfection by centrifugation and filtered using 0.2 μm PES vacuum sterile single-use filter unit (Thermo Scientific, Cat. No. 5670020). Purification was performed with Ni-NTA resin (Invitrogen, Cat. No. 60-0442). The supernatant was transferred to a 25 mL column for gravity flow chromatography with the resin and washed with PBS pH 7.2. The protein was eluted with buffer containing PBS, 250 mM NaCl, 250 mM imidazole pH 7.2 and buffer exchange was performed with PBS pH 7.2 using a 10 kDa Amicon Ultra-15 Centrifugal Filter Unit. Final purification was performed by prepSEC at 4 °C using either Superdex 200 Increase 10 / 300 GL or HiLoad 16 / 600 Superdex 200 pg at a flow rate of 0.75 mL / min, with PBS pH 7.2. SDS-PAGE analysis was executed using Invitrogen XCell SureLock mini-Cell blot module (Invitrogen, Cat. No. EI0002), followed by staining using InstantBlue Coomassie Protein Stain (Abcam, Cat. No. ab119211). Analytical size exclusion chromatography (anSEC) was performed on an Agilent Chemstation HPLC-SEC with a Sepax-Zenix SEC-300 gel filtration column. LC-MS Atty Docket No.: NHWK-003WO analysis was performed on an Agilent 6545XT AdvanceBio LC / Q-TOF TF 1.8.1 with an Agilent AdvanceBio Desalting-RP Column. Materials & Methods: ELISA protocol for measuring subclass-specific cleavage potency. Maxisorp 96 well black plates (ThermoScientific, Cat. No.437111) were first coated with the respective IgG antigen (produced in-house) at a concentration of 10 µg / mL diluted in PBS, pH 7.2 and incubated overnight at 4 °C. For IgG1, IgG3, and IgG4 evaluations, recombinant TNFα was used as the coating antigen for Adalimumab with an IgG1, IgG3, and IgG4 backbone. For IgG2 evaluations, Satralizumab was used, and the plate was coated with its respective antigen, IL6R. The plates were then blocked with PBS, pH 7.5, 25 µM EDTA, 0.1% Tween-20, 1% BSA for 1 hour at room temperature. The plate was then washed 3 times with PBS, 0.05% Tween-20 (wash buffer) using an Agilent BioTek 405 TS Microplate washer. 100 µL of the antibody test article at 10 µg / mL was added and allowed to incubate for 30 minutes at room temperature while shaking at 400 rpm. The plates were again washed. A 1:3 dilution series of 120 µL of IdeS or IdeCanis variants was prepared in PBS, pH 7.4, 0.05% Tween-20, with the top concentration varying from 2 to 32 µM depending on the activity of the construct.100 µL of the IdeS construct dilution series was then added to the plates and allowed to incubate at 37 °C in an incubator while shaking at 200 rpm for 2 hours. After incubation at 37 °C, the plate was washed 3 times to remove IdeS and cleaved IgG Fc product. For IgG1 potency evaluations, a Mouse Anti-human IgG1 Fc AlexaFluor™ 488 (ThermoFisher, Cat. No. A-10631) was added to the wells and incubated for 15 minutes at room temperature. The plate was then washed 3 times to remove unbound antibody and the wells were read on an Envision 2105 Multi-Mode Plate Reader with excitation filter at 485 nm and emission filter 535 nm. For IgG2 potency evaluations, a Mouse Anti-human IgG2 Fc-HRP (SouthernBiotech, Cat. No.9060-05) was added to wells and incubated at room temperature for 15 minutes. The plate was then washed 3 times to remove unbound antibody, and 100 µL of QuantaBlu ™ Fluorogenic Substrate (ThermoFisher, Cat. No.15162) was added to the wells. After 15 minutes, the wells were read on the Envision plate reader with an excitation filter at 320 nm and emission filter at 460 nm. The same protocol for detection was used for IgG3 and IgG4 potency evaluations, but the detection antibody was a Mouse anti-Human IgG Fc (CH2) domain, HRP antibody (ThermoFisher, Cat. No. MA5-16859). Initially, all IdeCanis variants were screened using a single dilution series, with wild-type Atty Docket No.: NHWK-003WO IdeS used on every plate. If the construct showed activity, the assay was rerun using a duplicate dilution series for each construct, again with wild-type IdeS used on every plate to compare between plates and assay variability. FIG. 8 only shows the results of active variants that were run in duplicate. The potency curves were evaluated using GraphPad Prism version 9.0.0(121). IdeS construct concentrations in each well were graphed against the reporter signal and fit to non- linear regression absolute EC50. The baseline and bottom in the fit were constrained to the lowest signal on each plate, which was always one of the highest concentration WT IdeS wells. The EC50 values for each IdeS construct were then divided by the EC50 value of the WT IdeS control, and the resulting fold-change value reported. Results & Conclusions FIG. 8 shows the EC50 curves for each IgG subclass and TABLE 4 summarizes the fold change in comparison to IdeS. TABLE 4 IgG subtype cleavage summary of fold-change in comparison to IdeS Protein name I G1 I G2 I G3 I G4 The ELISA data corresponds well with the cleavage observations from the SDS-PAGE visualization of IgG cleavage, where at least ++ SDS-PAGE signal resulted in a measurable EC50 in the ELISA. In the potency ELISA, IgG1 cleavage was detectable in variants M2, M23, M123, M24, and M234. M23 and M234 were the most reactive variants at only 2.6-fold and 7.3-fold less potent Atty Docket No.: NHWK-003WO than wild-type IdeS, respectively. Although it seems that loop 2 is required for IgG1 activity, the combination with loop 1 in M12 did not show any cleavage of IgG1. There were only two IdeCanis variants that showed activity for IgG2, M23 and M234, which showed a 42-fold and 129-fold reductions in activity compared to wild-type IdeS, respectively. Interestingly, the low activity observed in IgG2 for M123 in the SDS-PAGE was not detectable in the ELISA potency assay. IgG3 and IgG4 cleavage was observed in many more of the IdeCanis variants. For IgG3 and IgG4, M2, M3, M12, M23, M123, M24, M234, M124 showed measurable EC50 values. M23, M2, and M234 displayed the highest IgG3 cleavage potencies of the IdeCanis variants at only 4-fold, 16-fold, and 18-fold below wild-type IdeS, respectively. M23 and M234 also performed well against IgG4. M23 potency showed a 0.5x increase in potency compared to wild-type IdeS, while M234 only showed a ~2-fold reduction in potency. These data clearly demonstrate that several different selectivity profiles have been engineered into an inactive IdeCanis IgG protease. M2-IdeCanis displays high activity for IgG1, IgG3, and IgG4 while sparing cleavage of IgG2. M12-IdeCanis shows very low activity for IgG3, but moderate activity for IgG4 at 67-fold decreased potency in comparison to IdeS, essentially creating an IgG4-selective IgG degrader. Both M23- and M234-IdeCanis show pan activity for all human IgG subclasses, but M23 displays better potency on all subclasses. Overall, novel IdeCanis variants have been engineered for potent human IgG substrate activity. At the same time, these engineered variants will evade the pre-existing anti-drug antibodies in patients that normally neutralize and inhibit IdeS activity. EXAMPLE 9: Examining pre-existing ADA of IdeCanis variants to determine if ADA binding increased with loop mutations. To quantify pre-existing ADA binds to the IdeCanis variants, a competitive ADA ELISA was utilized. See Example 3 for detailed protocol for the assay. All proteins were tested as inactive C65S variants to avoid cleavage of serum IgG. Results & Conclusions: FIG.9 depicts the percent of pre-existing ADA in pooled human serum that interacts with IdeCanis variants. The variants showed reductions in binding to ADA in comparison to IdeS. IdeCanis, M2-IdeCanis, M12-IdeCanis, and M23-IdeCanis were tested for binding to the pre- Atty Docket No.: NHWK-003WO existing ADA and displayed reductions of 65.4, 66.7, 63.1, and 63.7 %, respectively, in comparison to IdeS. Overall, this validates using a non-human pathogenic IgG degrader to avoid pre-existing ADA binding. References Åkesson, P., Moritz, L., Truedsson, M., Christensson, B., & Von Pawel-Rammingen, U. (2006). IdeS, a Highly Specific Immunoglobulin G (IgG)-Cleaving Enzyme from Streptococcus pyogenes, Is Inhibited by Specific IgG Antibodies Generated during Infection. Infection and Immunity, 74(1), 497. https: / / doi.org / 10.1128 / IAI.74.1.497-503.2006 Huijbers, M. G., Plomp, J. J., van der Maarel, S. M., & Verschuuren, J. J. (2018). IgG4-mediated autoimmune diseases: a niche of antibody-mediated disorders. Annals of the New York Academy of Sciences, 1413(1), 92. https: / / doi.org / 10.1111 / NYAS.13561 Koneczny, I. (2020). Update on IgG4-mediated autoimmune diseases: New insights and new family members. Autoimmunity Reviews, 19(10), 102646. https: / / doi.org / 10.1016 / J.AUTREV.2020.102646 Lei, B., DeLeo, F. R., Hoe, N. P., Graham, M. R., Mackie, S. M., Cole, R. L., Liu, M., Hill, H. R., Low, D. E., Federle, M. J., Scott, J. R., & Musser, J. M. (2001). Evasion of human innate and acquired immunity by a bacterial homolog of CD11b that inhibits opsonophagocytosis. Nature Medicine, 7(12), 1298–1305. https: / / doi.org / 10.1038 / NM1201-1298 Lei, B., DeLeo, F. R., Reid, S. D., Voyich, J. M., Magoun, L., Liu, M., Braughton, K. R., Ricklefs, S., Hoe, N. P., Cole, R. L., Leong, J. M., & Musser, J. M. (2002). Opsonophagocytosis-inhibiting Mac protein of group A Streptococcus: Identification and characteristics of two genetic complexes. Infection and Immunity, 70(12), 6880–6890. https: / / doi.org / 10.1128 / IAI.70.12.6880-6890.2002 / ASSET / 7AA60410-8F67-445E-A1C3- C55F55549B23 / ASSETS / GRAPHIC / II1220755007.JPEG Sudol, A. S. L., Butler, J., Ivory, D. P., Tews, I., & Crispin, M. (2022). Extensive substrate recognition by the streptococcal antibody-degrading enzymes IdeS and EndoS. Nature Communications 202213:1, 13(1), 1–11. https: / / doi.org / 10.1038 / s41467-022-35340-z Vincents, B., Von Pawel-Rammingen, U., Björck, L., & Abrahamson, M. (2004). Enzymatic characterization of the streptococcal endopeptidase, ides, reveals that it is a cysteine protease with strict specificity for IgG cleavage due to exosite binding. Biochemistry, 43(49), 15540–15549. https: / / doi.org / 10.1021 / BI048284D Volkov, M., Coppola, M., Huizinga, R., Eftimov, F., Huizinga, T. W. J., van der Kooi, A. J., Oosten, L. E. M., Raaphorst, J., Rispens, T., Sciarrillo, R., Titulaer, M. J., Wieske, L., Toes, R. E. M., Huijbers, M. G. M., van Schie, K. A., & van der Woude, D. (2022). Comprehensive overview of autoantibody isotype and subclass distribution. Journal of Allergy and Clinical Immunology, 150(5), 999–1010. https: / / doi.org / 10.1016 / J.JACI.2022.05.023 / ATTACHMENT / A7E9FB20-5305-4FFA-B529- A6F3F57B4232 / MMC2.DOCX Von Pawel-Rammingen, U., & Björck, L. (2003). IdeS and SpeB: Immunoglobulin-degrading cysteine proteinases of Streptococcus pyogenes. Current Opinion in Microbiology, 6(1), 50– 55. https: / / doi.org / 10.1016 / S1369-5274(03)00003-1 Atty Docket No.: NHWK-003WO Von Pawel-Rammingen, U., Johansson, B. P., & Björck, L. (2002). IdeS, a novel streptococcal cysteine proteinase with unique specificity for immunoglobulin G. The EMBO Journal, 21(7), 1607. https: / / doi.org / 10.1093 / EMBOJ / 21.7.1607 Zhang, H., Li, P., Wu, D., Xu, D., Hou, Y., Wang, Q., Li, M., Li, Y., Zeng, X., Zhang, F., & Shi, Q. (2015). Serum IgG Subclasses in Autoimmune Diseases. Medicine, 94(2), e387. https: / / doi.org / 10.1097 / MD.0000000000000387

Claims

Atty Docket No.: NHWK-003WO CLAIMS WE CLAIM:

1. A polypeptide having human IgG cleavage activity and comprising an amino acid sequence having at least 85% sequence identity to the amino acid sequence set forth in SEQ ID NO:2, wherein the polypeptide comprises the amino acids: (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232, based on the numbering of the amino acid sequence of SEQ ID NO:2; and / or (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289, based on the numbering of the amino acid sequence of SEQ ID NO:

2.

2. The polypeptide of claim 1, wherein the amino acid sequence has at least 90% sequence identity to the amino acid sequence set forth in SEQ ID NO:

2.

3. The polypeptide of claim 1 or 2, wherein the amino acid sequence has no more than 94% to 98% sequence identity to the amino acid sequence set forth in SEQ ID NO:

2.

4. The polypeptide of any one of claims 1-3, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232.

5. The polypeptide of claim 4, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

4.

6. The polypeptide of any one of claim 1-3, wherein the amino acid sequence comprises the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289.Atty Docket No.: NHWK-003WO 7. The polypeptide of claim 6, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

5.

8. The polypeptide of any one of claims 1-4, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140.

9. The polypeptide of claim 8, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

6.

10. The polypeptide of any one of claims 1-3, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289.

11. The polypeptide of claim 10, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

7.

12. The polypeptide of any one of claims 1-3 and 10, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140.Atty Docket No.: NHWK-003WO 13. The polypeptide of claim 12, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

9.

14. The polypeptide of any one of claims 1-4, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202.

15. The polypeptide of claim 14, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

11.

16. The polypeptide of any one of claims 1-3 and 10, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202.

17. The polypeptide of claim 16, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

12.

18. The polypeptide of claim 8, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202.Atty Docket No.: NHWK-003WO 19. The polypeptide of claim 18, wherein the the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

13.

20. The polypeptide of any one of claims 1-4, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; and the amino acid N at position 307.

21. The polypeptide of claim 20, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

15.

22. The polypeptide of claim 8, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; and the amino acid N at position 307.

23. The polypeptide of claim 22, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

16.

24. The polypeptide of any one of claims 1-3 and 10, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; and the amino acid N at position 307.

25. The polypeptide of claim 24, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 17.Atty Docket No.: NHWK-003WO 26. The polypeptide of claim 16, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acids (iv) H at position 196, D at position 197, K at position 199, N at position 200, G at position 202; and the amino acid N at position 307.

27. The polypeptide of claim 26, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

18.

28. The polypeptide of claim 22, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (iii) Y at position 134, T at position 137, K at position 138, H at position 139, L at position 140; the amino acid N at position 307; and the amino acid N at position 187.

29. The polypeptide of claim 28, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

23.

30. The polypeptide of claim 24, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, and N at position 232; the amino acids (ii) E at position 283, K at position 285, E at position 286, D at position 287, N at position 288, and I at position 289; the amino acid N at position 307; and the amino acid N at position 187.

31. The polypeptide of claim 30, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 24.Atty Docket No.: NHWK-003WO 32. The polypeptide of claim 20, wherein the amino acid sequence comprises the amino acids (i) G at position 221, L at position 222, A at position 227, V at position 229, R at position 230, N at position 232; the amino acid N at position 307; and the amino acid N at position 187.

33. The polypeptide of claim 32, wherein the amino acid sequence has at least 85%, at least 90%, at least 95%, or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO:

25.

34. The polypeptide of any one of claims 1 to 33, wherein the amino acid sequence has no more than 80% sequence identity to IdeS having the amino acid sequence set forth in SEQ ID NO:1 and wherein the polypeptide does not bind to anti-IdeS antibodies.

35. The polypeptide of claim 34, wherein the anti-IdeS antibody is present in a human subject previously treated with IdeS or exposed to IdeS via Streptococcus pyogenes infection.

36. A pharmaceutical composition comprising a polypeptide of any one of claims 1 to 35 and a pharmaceutically acceptable carrier.

37. A nucleic acid encoding a polypeptide of any one of claims 1-35.

38. A recombinant expression vector comprising the nucleic acid of claim 37.

39. A host cell comprising the nucleic acid of claim 37 or the recombinant expression vector of claim 38.

40. A method for treating a human subject previously exposed to IdeS, comprising administering to the human subject an effective amount of a polypeptide of any one of claims 1-35; a pharmaceutical composition of claim 36; a nucleic acid encoding a polypeptide of any one of claims 1-35; a recombinant expression vector comprising the nucleic acid of claim 38; or a host cell comprising the nucleic acid of claim 37 or theAtty Docket No.: NHWK-003WO recombinant expression vector of claim 38, wherein the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell has human IgG cleavage activity in the human subject and wherein the administering does not induce an anti-IdeS antibody response in the human subject.

41. The method of claim 40, wherein the subject has pre-existing anti-IdeS antibody against IdeS having amino acid sequence of SEQ ID NO:

1.

42. A method for treating or preventing a disease or condition mediated by IgG antibodies in a human subject in need thereof, comprising administering to the human subject a therapeutically effective amount of a polypeptide of any one of claims 1-35; a pharmaceutical composition of claim 36; a nucleic acid encoding a polypeptide of any one of claims 1-35; a recombinant expression vector comprising the nucleic acid of claim 38; or a host cell comprising the nucleic acid of claim 37 or the recombinant expression vector of claim 38, wherein the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease.

43. The method of claim 39, wherein the disease mediated by IgG antibodies is an autoimmune disease.

44. A method of treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, comprising contacting the blood with a polypeptide of any one of claims 1-35.

45. The method of claim 44, wherein the blood is returned to the patient after contacting it with the polypeptide of any one of claims 1-35.

46. The method of claim 44 or 45, wherein the disease mediated by IgG antibodies is an autoimmune disease.Atty Docket No.: NHWK-003WO 47. A method of preparing a fragment of human IgG antibody, comprising: contacting the human IgG antibody with a polypeptide of any one of claims 1-35, wherein the polypeptide cleaves Fc hinge of the IgG antibody to generate a Fab fragment and a Fc fragment.

48. The method of claim 47, further comprising isolating the Fab or Fc fragment of the human IgG antibody.

49. The method of claim 47 or 48, wherein the human IgG antibody is human IgG1, IgG3, or IgG4 and the method comprises contacting the human IgG antibody with the polypeptide of any one of claims 1-35, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG3, and IgG4.

50. The method of claim 47 or 48, wherein the human IgG antibody is human IgG3 or IgG4 and the method comprises contacting the human IgG antibody with the polypeptide of any one of claims 1-35, wherein the polypeptide cleaves Fc hinge of the human IgG3 and IgG4.

51. The method of claim 47 or 48, wherein the human IgG antibody is human IgG1, IgG2, IgG3, or IgG4 and the method comprises contacting the human IgG antibody with the polypeptide of any one of claims 6-7, 10-17, 24-27 and 30-33, wherein the polypeptide cleaves Fc hinge of the human IgG1, IgG2, IgG3, and IgG4.

52. The method of claim 47 or 48, wherein: the human IgG antibody is human IgG2 and the method comprises contacting the human IgG2 antibody with the polypeptide of any one of claims 6-7, 10-17, 24-27 and 30-33, wherein the polypeptide cleaves Fc hinge of the human IgG2; or the human IgG antibody is human IgG4 and the method comprises contacting the human IgG4 antibody with the polypeptide of any one of claims 8-9 or 28-29, wherein the polypeptide cleaves Fc hinge of the human IgG4.Atty Docket No.: NHWK-003WO 53. A polypeptide of any one of claims 1-35; a pharmaceutical composition of claim 36; a nucleic acid encoding a polypeptide of any one of claims 1-35; a recombinant expression vector comprising the nucleic acid of claim 38; or a host cell comprising the nucleic acid of claim 37 or the recombinant expression vector of claim 38 for use in a method for treating a human subject previously treated with IdeS or exposed to IdeS via Streptococcus pyogenes infection, wherein the method comprises administering to the human subject an effective amount of the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell, wherein the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell has human IgG cleavage activity in the human subject, and wherein the administering does not induce an anti-IdeS antibody response in the human subject.

54. The polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell according to claim 53 for use in a method for treating a human subject previously treated with IdeS or exposed to IdeS via Streptococcus pyogenes infection, wherein the subject has pre-existing anti-IdeS antibody against IdeS having amino acid sequence of SEQ ID NO:

1.

55. A polypeptide of any one of claims 1-35; a pharmaceutical composition of claim 36; a nucleic acid encoding a polypeptide of any one of claims 1-35; a recombinant expression vector comprising the nucleic acid of claim 38; or a host cell comprising the nucleic acid of claim 37 or the recombinant expression vector of claim 38 for use in a method for treating a human subject suffering from a disease mediated by IgG antibodies, wherein the method comprises administering to the human subject a therapeutically effective amount of the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell, and wherein the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell has human IgG cleavage activity in the human subject and cleavage of human IgG treats the disease.Atty Docket No.: NHWK-003WO 56. The polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell according to claim 55 for use in a method for treating a human subject suffering from a disease mediated by IgG antibodies, wherein the disease mediated by IgG antibodies is an autoimmune disease.

57. A polypeptide of any one of claims 1-35; a pharmaceutical composition of claim 36; a nucleic acid encoding a polypeptide of any one of claims 1-35; a recombinant expression vector comprising the nucleic acid of claim 38; or a host cell comprising the nucleic acid of claim 37 or the recombinant expression vector of claim 38 for use in a method for treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, wherein the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell has human IgG cleavage activity in the human subject.

58. The polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell according to claim 57 for use in a method for treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, wherein the blood is returned to the patient after contacting it with the polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell.

59. The polypeptide, the pharmaceutical composition, the nucleic acid, the recombinant expression vector or the host cell according to claim 57 or 58 for use in a method for treating, ex vivo, blood taken from a patient suffering from a disease mediated by IgG antibodies, wherein the disease mediated by IgG antibodies is an autoimmune disease.

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