23 results about "Staphylococcal protein" patented technology

An Fc-binding polypeptide with improved alkaline stability comprising a mutant of the Fc-binding domain of Staphylococcus protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at a position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

The invention is applicable to the technical field of genetic engineering, and provides a vaccine for preventing and treating staphylococcus aureus mastitis and application of the vaccine. A recombinant bacillus subtilis construction method comprises the following steps: taking a DNA sequence as shown in SEQ ID NO.3 as a template, and performing PCR amplification to obtain a PCR product sequence; connecting the PCR product to a pHT43 vector, and converting the pHT43 vector into a competent cell DH5alpha, so as to obtain a recombinant plasmid pHT43-cCsa; the method comprises the following steps: transforming a recombinant plasmid pHT43-cCsa into a competent cell of bacillus subtilis WB800N, taking pHT43-F and pHT43-R as primers, and screening a positive transformant through a PCR (Polymerase Chain Reaction) technology; the recombinant bacillus subtilis for expressing the staphylococcus aureus Csa protein is constructed by utilizing a homologous recombination technology, so that pathological injury caused by staphylococcus aureus infection can be reduced, and staphylococcus aureus mastitis of dairy cattle can be prevented.

The present disclosure relates to a class of polypeptides derived from Staphylococcus Protein A (SpA) or any domain thereof, that exhibit an improved binding affinity for IgA. Moreover, IgA binding polypeptides that selectively bind IgA among other immunoglobulin isotypes are also provided. The present disclosure also relates to methods for isolating IgA, such as antibodies of isotype IgA, using said polypeptides as well as related products, such as separation matrices coupled to said IgA binding polypeptides and / or multimers thereof.

The present invention relates to mutated immunoglobulin-binding polypeptides. An Fc-binding polypeptide with improved base stability comprising a mutant of an Fc-binding domain of Staphylococcus Protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at the position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

In certain embodiments, the present invention provides novel antibody purification methods and systems using a potentially simple and cost-efficient means. In some embodiments, customized Z-33 derived from Staphylococcus aureus Protein A is used to construct immuno-amphiphile molecules which can assemble into immunofibers in aqueous solution with bioactive epitopes on the surface and have IgG binding ability.

This application discloses novel polypeptides, polynucleotides, expression vectors and novel immunogenic compositions derived from Staphylococcus aureus, in particular novel polypeptides, polynucleotides, expression vectors and compositions derived from / related to SpA, Hla, Aur and LukE polypeptides. Also disclosed is a method of immunization using polypeptides, polynucleotides, expression vectors, and immunogenic compositions.

The invention provides a universal purification method of a recombinant staphylococcus aureus protein antigen. The purification method comprises the steps of sample treatment and refined purification. Wherein the sample treatment comprises fermentation material liquid crushing, crushed sample clarification and clarified sample concentration; the fine purification comprises primary purification, medium purification and fine purification; the recombinant staphylococcus aureus protein antigen is recombinant staphylococcus aureus enterotoxin A, enterotoxin B, enterotoxin C2 and / or toxic shock syndrome toxin 1. The purification method meets the quality standard required by pharmacopeia, also has the advantages of high yield, simple process, easy amplification and low cost, and greatly simplifies the production and preparation work of the recombinant staphylococcus aureus enterotoxin A, enterotoxin B, enterotoxin C2 and toxic shock syndrome toxin 1.

An Fc-binding polypeptide with improved alkaline stability comprising a mutant of the Fc-binding domain of Staphylococcus protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at a position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

The present application provides a polypeptide with binding affinity to HPV18 E6 protein, taking the Z domain of staphylococcal protein A as a scaffold, randomly mutating the surface amino acid residues to simulate antibody binding sites, constructing a mutant library through phage display technology, screening the library through affinity with HPV18 E6 as a target antigen, and finally obtaining a polypeptide with high affinity to HPV18 E6 through a large number of screening work. Through in-depth research, the present application first discloses a polypeptide with binding affinity to the E6 protein of HPV18. In addition, the present application also provides the diagnostic or therapeutic use of the polypeptide as a drug or molecular targeting reagent.

Novel polypeptides, polynucleotides, expression vectors and novel immunogenic compositions derived from Staphylococcus aureus, in particular novel polypeptides, polynucleotides, expression vectors and compositions derived from / related to the SpA, Hla, Aur and LukE polypeptides. Also disclosed is methods of immunity induction utilising the polypeptides, polynucleotides, expression vectors, and immunogenic compositions.

The present invention relates to the field of biomedicine, and more specifically, to a polypeptide with binding affinity for Epstein-Barr virus nuclear antigen 1 (EBNA1) and its use. The present invention provides a polypeptide with binding affinity for EBNA1, using EBNA1 as the target antigen. The inventors used the Z domain of Staphylococcus protein A as a scaffold, randomly mutated its surface amino acid residues to mimic antibody binding sites, constructed a mutant library using phage display technology, and subjected this library to affinity screening using EBNA1 as the target antigen. After extensive screening, a polypeptide with high affinity for EBNA1 was ultimately obtained. After in-depth research, the present invention discloses a polypeptide with binding affinity for EBNA1. Furthermore, the present invention provides the use of this polypeptide as a drug or molecular targeting agent for diagnosis or treatment.

The present invention relates to chromatography ligands having improved caustic stability, e.g., ligands based on immunoglobulin-binding proteins such as, Staphylococcal protein A, as well as methods of making and using such ligands.

The present disclosure relates to a class of polypeptides derived from a Staphylococcus Protein A (SpA) or a domain thereof that enables mild elution, such as elution within a pH range of pH 4.4-6.0, for the efficient isolation of immunoglobulins. Methods for isolating immunoglobulins using mild elution as well as related products, such as separation matrices coupled to the herein disclosed polypeptides or the multimers thereof, are also disclosed.

The present invention relates to mutated immunoglobulin-binding polypeptides. An Fc-binding polypeptide with improved base stability comprising a mutant of an Fc-binding domain of Staphylococcus Protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at the position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

An Fc-binding polypeptide with improved alkaline stability comprising a mutant of the Fc-binding domain of Staphylococcus protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at a position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

The invention relates to a method of isolating an immunoglobulin, comprising the steps of: a) providing a separation matrix comprising multimers of immunoglobulin-binding alkali-stabilized Protein A domains covalently coupled to a porous support: b) contacting a liquid sample comprising an immunoglobulin with the separation matrix; c) washing said separation matrix with a washing liquid; d) eluting the immunoglobulin from the separation matrix with an elution liquid, and e) cleaning the separation matrix with a cleaning liquid, wherein the alkali-stabilized Protein A domains comprise mutants of a parental Fc-binding domain of Staphylococcus Protein A (SpA).

The invention discloses an immunoglobulin binding protein with high alkali stability and application thereof, and relates to the field of biology, a z structure (SEQ ID NO.1) of staphylococcus protein A is subjected to a series of directed mutation or structural design, and the mutant comprises at least one mutation or all mutations selected from Q55A and A46G sites. On the basis of the z structure of the protein A, the z structural domain of the protein A is modified through protein engineering and bioinformatics analysis in combination with a site-directed mutagenesis biotechnology, so that the alkali resistance of the protein A is improved. A recombinant protein A affinity chromatography medium is prepared, and the static adsorption capacity, the dynamic loading capacity, the alkali resistance and the reuse performance of the recombinant protein A affinity chromatography medium are tested.

The invention provides a method for improving the expression quantity of recombinant staphylococcus aureus protein A. The method comprises the following steps: inoculating a recombinant staphylococcus aureus protein A strain into a YPD culture medium for activation; sequentially inoculating the activated strains into a BMGY composite culture medium containing coffee seed polyphenol and juglone and a BMMY composite culture medium containing myrobalan tannin and neoandrographolide for amplification and induction culture, finally harvesting cells, and measuring the expression quantity of the recombinant staphylococcus aureus protein A. Aiming at the strain growth characteristics in the culture process of the recombinant staphylococcus aureus protein A, an innovative optimization strategy is provided on the basis of BMGY and BMMY culture media commonly used in a yeast expression system: in different stages of strain amplification and induction, an amplification culture medium and an induction culture medium which are specially matched are respectively used, and according to the strain requirements of each stage, the culture medium and the induction culture medium are used for amplification and induction; different natural compounds are added. According to the staged and differentiated culture mode, proliferation of the strain can be remarkably promoted, the yield of the recombinant staphylococcus aureus protein A can be effectively increased, the problem that the expression quantity of the recombinant staphylococcus aureus protein A is low at present is successfully solved, and the expression quantity is remarkably increased.

The present invention discloses a non-diagnostic African swine fever virus antibody detection method, the steps are: infecting wild boar kidney cells with a microbial deposit number of CCTCC NO: C2022258 with an African swine fever virus strain with a microbial deposit number of CCTCC NO: V202404 in a 96-well plate, fixing the infected cells in the wells of the 96-well plate, adding serum to be tested to the 96-well plate, adding HRP-labeled recombinant staphylococcal protein A to the wells, adding AEC color developing solution to the wells, washing the 96-well plate, observing the 96-well plate with an ordinary optical microscope, and judging whether the serum contains African swine fever virus antibodies based on whether reddish-brown stained cells can be observed. The present invention also discloses a virus strain and a kit for the above-mentioned detection method. The method has high sensitivity, good safety, good specificity, convenient operation, and can be promoted and applied.

The present invention relates to chromatographic ligands having improved corrosion stability, such as ligands based on immunoglobulin binding proteins, such as Staphylococcus protein A, and methods of making and using the same.

The present invention relates to mutated immunoglobulin-binding polypeptides. An Fc-binding polypeptide with improved base stability comprising a mutant of an Fc-binding domain of Staphylococcus Protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at the position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

This disclosure relates to a class of peptides derived from Staphylococcus Protein A (SpA) or its domains, which achieve mild elution, such as elution in a pH range of 4.4–6.0, for the efficient separation of immunoglobulins. Methods for separating immunoglobulins using mild elution and related products, such as separation matrices coupled with the peptides or their multimers disclosed herein, are also disclosed.

We describe novel Staphylococcal Protein A ligands that enable milder elution pH for use in affinity chromatography. The change in elution pH is the result of point mutations to the protein sequence. Two novel ligands are investigated in this study. The first, designated Z(H18S)4, represents a histidine to serine substitution single mutation. The second, designated Z(H18S, N28A)4, is a double mutant comprising histidine to serine and asparagine to alanine mutations. Both are compared against the unmutated sequence, designated Z4, which is currently utilized in a commercially available Protein A stationary phase for the purification of molecules containing Fc domains. The ligands are coupled to a chromatography support matrix and tested against a panel of antibodies and an Fc fusion protein for elution pH, dynamic binding capacity, step-wise elution, and capture from clarified culture media. Results demonstrate that the novel ligands result in milder elution pH, on average >0.5 pH units, when tested in a pH gradient. For step-wise elution at pH 4.0, the Z(H18S, N28A)4 ligand showed on average a greater than 30% increase in yield compared to Z4. Importantly, for the antibodies tested the mutations did not result in a decrease in dynamic binding capacity or other desirable attributes such as selectivity. A potential application of the novel ligands is shown with a pH sensitive molecule prone to aggregation under acidic conditions.