789 results about "Amino acid substitution" patented technology

The present inventors provide methods for modifying the isoelectric point of an antibody while retaining its antigen-binding activity, comprising modifying the charge of at least one exposable amino acid residue on the surface of the complementarity determining region (CDR). The present invention also provides methods for purifying multispecific antibodies, comprising modifying isoelectric point, and methods for improving the plasma pharmacokinetics of antibodies, comprising modifying isoelectric point. The present invention further provides antibodies with a modified isoelectric point, pharmaceutical compositions comprising the antibodies as an active ingredient, and methods for producing the antibodies and compositions.

The present invention provides for a modified antibody of class IgG, in which at least one amino acid from the heavy chain constant region selected from the group consisting of amino acid residues 250, 314, and 428 is substituted with another amino acid which is different from that present in the unmodified antibody, thereby altering the binding affinity for FcRn and/or the serum half-life in comparison to the unmodified antibody.

The present invention concerns a method to detect the presence of an enzyme in in vivo or in vitro tissue or cell, which method comprises:(a) obtaining a tissue or cell sample to be analyzed;(b) contacting the tissue or cell sample with a substrate of the structure selected from the group consisting of:X=H or one or more natural or synthetic amino acids with or without amino blocking groups,Y=H or one or more natural or synthetic amino acids with or without amino blocking groups,wherein X and Y are the same or different and are amino acid sequences of between about 1 to 1,000,000 amino acids wherein each amino acid is the same or a different amino acid, with the proviso that at least one of X or Y is at least one amino acid;(c) when an enzyme is present in the tissue or cell sample which degrades X, Y and combinations thereof, fluorescent cresyl violet is released in the tissue sample producing a color change;(d) detecting the presence and amount of the enzyme present by the detection and quantification of the fluorescence produced; and(e) optionally comparing the fluorescence to a pre-calibrated fluorescence scale to quantify the fluorescence present. A diagnostic kit for use and a method to prepare amino acid cresyl violet derivatives are described.

A mutant cholera holotoxin featuring a point mutation at amino acid 29 of the A subunit, wherein the glutamic acid residue is replaced by an amino acid other than aspartic acid, is useful as an adjuvant in an antigenic composition to enhance the immune response in a vertebrate host to a selected antigen from a pathogenic bacterium, virus, fungus or parasite. In a particular embodiment, the amino acid 29 is histidine. The mutant cholera holotoxin may contain at least one additional mutation in the A subunit at a position other than amino acid 29. The antigenic composition may include a second adjuvant in addition to the mutant cholera holotoxin.

The present invention provides antigen binding proteins that specifically bind to Wilms' tumor protein (WT1), including humanized, chimeric and fully human antibodies against WT1, antibody fragments, chimeric antigen receptors (CARs), fusion proteins, and conjugates thereof. The antigen binding proteins and antibodies bind to HLA-A0201-restricted WT1 peptide. Such antibodies, fragments, fusion proteins and conjugates thereof are useful for the treatment of WT1 associated cancers, including for example, breast cancer, ovarian cancer, prostate cancer, chronic myelocytic leukemia, multiple myeloma, acute lymphoblastic leukemia (ALL), acute myeloid/myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). In more particular embodiments, the anti-WT1/A antibodies may comprise one or more framework region amino acid substitutions designed to improve protein stability, antibody binding and/or expression levels.

Rationally designed antibodies and polypeptides that comprise multiple Fc region amino acid substitutions that synergistically provide enhanced selectivity and binding affinity to a target Fc receptor are provided. The polypeptides are mutated at multiple positions to make them more effective when incorporated in antibody therapeutics than those having wild-type Fc components.

A mutant hydrolase optionally fused to a protein of interest is provided. The mutant hydrolase is capable of forming a bond with a substrate for the corresponding nonmutant (wild-type) hydrolase which is more stable than the bond formed between the wild-type hydrolase and the substrate and has at least two amino acid substitutions relative to the wild-type hydrolase. Substrates for hydrolases comprising one or more functional groups are also provided, as well as methods of using the mutant hydrolase and the substrates of the invention. Also provided is a fusion protein capable of forming a stable bond with a substrate and cells which express the fusion protein.

Methods for identifying one or more amino acid substitutions in a Rubisco large subunit polypeptide (variant) that confer increased Rubisco activity in a unicellular photosynthetic organism and transferring those substitutions to a Rubisco large subunit polypeptide of a higher plant cell are described herein. Methods and compositions for modulating plant productivity using the modified Rubisco large subunit polypeptide variants are provided. The Rubisco large subunit sequences are used in a variety of methods including increasing plant productivity in a plant. Transformed plants, plant cell, tissues, seed, and expression vectors are also provided.

The invention provides a method for identifying positions of an antibody that can be modified without significantly reducing the binding activity of the antibody. In many embodiments, the method involves identifying a substitutable position in a parent antibody by comparing its amino acid sequence to the amino acid sequences of a number of related antibodies that each bind to the same antigen as the parent antibody. The amino acid at the substitutable position may be substituted for a different amino acid without significantly affecting the activity of the antibody. The subject methods may be employed to change the amino acid sequence of a CDR without significantly reducing the affinity of the antibody of the antibody, in humanization methods, or in other antibody engineering methods. The invention finds use in a variety of therapeutic, diagnostic and research applications.

Modified glucagon peptides are disclosed having improved solubility and/or half-life while retaining glucagon agonist activity. The glycogen peptides have been modified by substitution of native amino acids with, and/or addition of, charged amino acids to the carboxy terminus of the peptide. The modified glucagon agonists can be further modified by pegylation, or the addition of a carboxy terminal peptide selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 23, or both to further enhance the solubility of the glucagon agonist analogs.

Some embodiments relate to analogs of peptides corresponding to class I MHC-restricted T cell epitopes and methods for their generation. These analogs can contain amino acid substitutions at residues that directly interact with MHC molecules, and can confer improved, modified or useful immunologic properties. Additionally classes of analogs, in which the various substitutions comprise the non-standard residues norleucine and/or norvaline, are disclosed.

The present invention provides humanized, chimeric and human anti-CD19 antibodies, anti-CD19 antibody fusion proteins, and fragments thereof that bind to a human B cell marker. Such antibodies, fusion proteins and fragments thereof are useful for the treatment and diagnosis of various B-cell disorders, including B-cell malignancies and autoimmune diseases. In more particular embodiments, the humanized anti-CD19 antibodies may comprise one or more framework region amino acid substitutions designed to improve protein stability, antibody binding and/or expression levels. In a particularly preferred embodiment, the substitutions comprise a Ser91Phe substitution in the hA19 VH sequence.

Described herein are, proteins comprising amino acid substitutions in at least one of a first and a second polypeptide chain. Furthermore, is described the uses and methods related to said proteins.

Methods and systems for the discovery of high-affinity peptide ligands and the resulting compositions are described herein. The amino acid sequence of a target protein is used to identify one or more homologous proteins of the target protein. Publications and databases are textmined to retrieve the sequences of peptide ligands that bind to the homologues or the target protein. Complementary proteins, which are proteins that bind to the target or homologous proteins or to DNA, and their target protein- or DNA-binding regions may also be identified. These candidate ligands are predicted to have a high probability of binding to the target protein or the DNA. The library of candidate peptide ligands is modulated by substituting native amino acid residues with suitable amino acids, thus increasing the explored protein space in a knowledge-based manner. Peptides designed in the modulation step are experimentally screened to identify high-affinity binding ligands, and further optimized through iterative application of the modulation and screening steps.

To solve the above-mentioned problems, the present inventors introduced site-specific mutations into sc(Fv)2 and examined the stabilizing effects on sc(Fv)2. As a result, they succeeded for the first time in significantly increasing the Tm value of sc(Fv)2 by amino acid substitutions. Furthermore, they discovered that sc(Fv)2 is stabilized by introducing site-specific mutations into sc(Fv)2.