52 results about "STAPH PROTEIN A" patented technology

An Fc-binding polypeptide of improved alkali stability, comprising a mutant of an Fc-binding domain of Staphylococcus Protein A (SpA), as 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 SEQ 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.

The present invention relates to a chromatography ligand, which comprises Domain C from Staphylococcus protein A (SpA), or a functional fragment or variant thereof. The chromatography ligand presents an advantageous capability of withstanding harsh cleaning in place (CIP) conditions, and is capable of binding Fab fragments of antibodies. The ligand may be provided with a terminal coupling group, such as arginine or cysteine, to facilitate its coupling to an insoluble carrier such as beads or a membrane. The invention also relates to a process of using the ligand in isolation of antibodies, and to a purification protocol which may include washing steps and/or regeneration with alkali.

The invention discloses a polypeptide with improved alkaline stability, which polypeptide comprises a mutant of a B or C domain of Staphylococcus Protein A (SpA), as specified by SEQ ID NO 1 or SEQ ID NO 2, or of Protein Z, as specified by SEQ ID NO 3, comprising at least the mutation wherein the glutamine residue at position 9 has been mutated to a tryptophan, leucine, glutamic acid, valine or lysine. The invention also discloses multimers of the polypeptide, as well as separation matrices comprising the multimers or polypeptides.

A polypeptide with improved alkaline stability, which polypeptide comprises a mutant of a B or C domain of Staphylococcus Protein A, as specified by SEQ ID NO 1 or SEQ ID NO 2, or of Protein Z, as specified by SEQ ID NO 3, wherein at least the glutamine residue at position 9 has been mutated to an amino acid other than asparagine. The invention also discloses multimers of said polypeptide, as well as separation matrices comprising the multimers or polypeptides.

Provided are Staphylococcal protein A (SpA) variants for binding immunoglobulin (Ig), comprising a polypeptide which varies by one or more amino acids from the amino acid sequence of a natural variable heavy chain III (“VH3”) Ig-Fab binding region (“binding region”) of SpA, wherein the polypeptide exhibits a different binding specificity for Ig-Fab than does SpA or exhibits a different binding specificity for a non-Ig target molecule than does SpA. Further provided are methods of making the variants and methods of using the variants for in purification of Ig as well as diagnostic and therapeutic intervention.

The invention provides a protein A immunoadsorption material which eliminates pathogenic antibody and the compound from plasma and the a preparation method. The invention discloses a polymer material coupled by agarose gel and staphylococcal protein A (SPA) and the material takes the agarose gel as vector matrix and takes polyamines reagent as a space arm, then reacting with glutaraldehyde and finally coupling with the protein A and blocking, reducing a double bond after being activated by epoxy bromopropane. The product has the high safety; by making use of the produce, the pathogenic antibody, more particularly, the immune compound pathogenic antibody can be effectively and selectively eliminated from the plasma of patients; and the invention can be applied to clinical immunoadsorption treatments.

A polypeptide is provided, which has a binding affinity for HER2 and which is related to a domain of staphylococcal protein A (SPA) in that the sequence of the polypeptide corresponds to the sequence of the SPA domain having from 1 to about 20 substitution mutations. Nucleic acid encoding the polypeptide, as well as expression vector and host cell for expressing the nucleic acid, are also provided. Also provided is the use of such a polypeptide as a medicament, and as a targeting agent for directing substances conjugated thereto to cells overexpressing HER2. Methods, and kits for performing the methods, are also provided, which methods and kits rely on the binding of the polypeptide to HER2.

A chemical luminous ligand analysis method for quantitatively checking human antibodies belongs to the biomedical technical field, which comprises: using the generality that staphylococcal protein A (SPA) can react with Fc point of IgG in mice; using the monoclonal antibody of high affinity and specificity to prepare a standard product to establish a standard curve; respectively reacting the monoclonal antibody and the antibody in the sample with enzyme-labeled antigens; using the nanometer magnetic particles coated by SPA as ligand to separate solid and liquid; and using enzymatic chemical illumination reaction catalyzed by horseradish peroxidase (HRP) to process illumination check; thereby establishing a chemical luminous ligand quantitative analysis on human antibodies. The chemical luminous ligand analysis method is suitable for quantitatively checking all human antibodies, for resolving the problem of prior art while most human antibodies can not be accurately and quantitatively checked, avoiding cross reaction and avoiding false negative result or false positive result.

The invention relates to a staphylococcal protein A (SPA) immunoadsorption material used for blood purification and a preparation method thereof. The invention discloses a macromolecule material which is coupled by agarose gel and SPA. The material is prepared by taking the agarose gel as carrier substrate which is reacted with epoxy bromopropane to obtain the epoxy-based active carrier; after that, polyamines reagent is taken as a space arm which is then reacted with carbonyl diimidazole and is then coupled with the SPA. The material has the advantages of short synthesis time, safe preparation, strong specificity of product, high adsorption efficiency and good regeneration performance to immunoglobulin and the compound thereof, and being able to be applied to clinic immunoadsorption cure.

The present invention discloses a performance improved recombination staphylococcus aureus protein A affinity ligand and a construction method thereof. The present invention adopts a molecular biology method. A sequence B of a nature protein A is selected for molecular transformation. A C-terminal of the sequence B is added with two cysteines, so that the protein A can pass through double-locus coupled chromatography matrix to stabilize the connection. Six glycines are added to the end of a second Loop of the sequence B to increase the length and reduce the binding force with an antibody, so that elution conditions are mild. On this basis, resistance performance to high concentration base of the protein A is transformed. Asparagines and phenylalanine at 23rd and 30th positions of the sequence B are respectively replaced by threonine and alanine to obtain a sequence Z with higher alkaline resistance properties. Then, isocaudarner is used for connecting sequence Zs of different numbers head-to-tail in series. The efficient expression system of e. coli is used for overexpression. The expressed recombination protein A is coupled to agarose matrix preparation affinity chromatography fillers and is used for purifying antibodies. Results show that the recombination protein A affinity ligand prepared by the present invention is good in elution performance and alkali resistance.

The invention discloses a gene of a recombinant staphylococal protein A and application thereof. The nucleotide sequence of the gene of the recombinant staphylococal protein A is shown as SEQ ID NO:1; and the amino acid sequence of the protein coded by the gene is shown as SEQ ID NO:2. The staphylococal protein A is fused with small ubiquitin to form the gene of the recombinant staphylococal protein A; the expressed recombinant protein facilitates purifying the protein and improves the stability and activity of the protein; and experiments prove that the bioactivity of the expressed recombinant staphylococal protein A is not obviously different from that of a natural staphylococal protein A. The recombinant staphylococal protein expression and purification method has the advantages of short production time, high expression efficiency, high expression level, simple purification and the like.

This invention discloses a multi-target quick test method for human immunodeficiency virus antibodies including: 1, expressing five kinds of HIV antigen white dribs and drabs-p24, gp41, gp36, gp120V3, gp120C in a colibacillus by a gene engineering technology, 2, fixing the five antigen whites on a pyroxylin film, 3, dripping armed serum on it and the virus antibody is combined with the antigen by a immunoreaction then adding the A(SPA) labeled by nm gold, 4, cleaning it after it penetrates the film, 5, adding SPA antibodies to increase the amplification to form red spots seen by eyes.

This invention discloses to a kind of immunofluorescence mark reagent box. It is a reagent box applied for the aspects of immunity mark which uses the green fluorescence protein (GFP) as the indicator, the staphylococcus protein A (SPA) as the antibody. It also discloses the preparation method of the reagent. This invention can applied wide range in the field such as the immunity fluorescence mark, immunity histochemistry, biochemistry analysis, antibody test, protein chip and so on. It can replace the exist product efficiently, its operation is more simple, stability, delicacy and reliability, it is especially the same with the high flux analysis which analyze by the fluorescence analysis instrument.

The invention relates to a quantificationally detecting method for autoantibody in vitro, belonging to biomedicine technical field. The general character that the staphylococcal bacteria protein A (SPA) can react with Fc site of IgG in human and mouse is skillfully used and monoclonal antibodies of high affinity and specificity are prepared into standard substance to establish standard curve, therefore the monoclonal antibodied and autoantibody in sample respectively react with the labelled antigens, and the SPA enveloped nm magnetic grains are used as ligands to perform solid-liquid separation, after radioactivity measurement of 125I, finally the radioactive ligand immunity quantitative analysis method of autoantibody is established. The said method is suitable for quantificationally detecting the autoantibody, so as to solve the problem that most of the antoantibody can not be accurately and quantificationally detected and at the same time prevent cross reaction without false negative or false positive phenomena.

Provided is staphylococcus protein A expressed by a mutational Staphylococcus aureus and its coding sequence, as well as a vector, host bacteria, composition or kit which contains the coding sequence of the mutational protein. Also provided is the use of the mutational protein and the composition thereof in the preparation of vaccines, therapeutic antibodies, diagnostic kits and the like, and for the prevention, treatment and detection of infections by Staphylococcus aureus. Also provided are methods for producing, fermenting and purifying the mutational protein.

The invention discloses a method of separating and purifying recombinant stphylococcl protein A. A series of impurities such as endotoxin, residual proteins (HCP) of escherichia coli, residual DNA escherichia coli and protein aggregates are effectively removed by adopting stuffing of two mixing mechanisms by way of two-step chromatography and ultrafiltration. The purest target sample is obtained by fewest steps, so that the process control cost is lowered, and the method has the characteristics of being good in stability, clear in process control index, suitable for scaled industrial production the like. The protein purity of a purified protein solution is greater than 97% by means of high performance liquid and SDS-PAGE electrophoresis; the protein recovery rate is greater than 75%; the endotoxin is reduced to 1EU/mg below; HCP and residual DNA of escherichia coli are lower than 5ppm, and the recombinant stphylococcl protein A can be used as a raw material for synthesizing clinical staphylococcus protein A immunosorbent.

The invention discloses a quantum dot fluorescence chromatography immunization analysis reagent for detecting human blood ZnT8A. The reagent comprises a base plate, a sample pad, a quantum dot-labeledcombination pad, a chromatography reaction membrane and a water absorption pad are arranged at the upper surface of the base plate, a quantum dot-labeled mouse-anti-human IgG antibody is absorbed atthe quantum dot-labeled combination pad, a detection line fixed with ZnT8 protein and a quality control line fixed with staphylococcal protein A are provided at the chromatography reaction membrane, to-be-detected human whole blood or a blood plasma sample are dropped to the sample pad, and are subjected to a chromatography reaction for 3-4 min, a fluorescence immunoassay analyzer is used for detecting the fluorescence intensity of the detection line and the quality control line, and the zinc transportprotein 8 self-antibody content in a sample can be calculated by built-in software. The reagent has the advantages of simple operation, fast reaction, high sensitivity, and strong specificity.

A pharmaceutical composition includes a purified antibody and a pharmaceutically acceptable carrier. The antibody can be a monoclonal antibody having both an antigen-binding portion that binds at least one bacterial antigen and a constant region that does not bind staphylococcal protein A.