20 results about "Immunoglobulin-binding protein" patented technology

The invention belongs to the technical field of protein engineering, and particularly relates to an immunoglobulin binding protein mutant with high alkali stability and application of the immunoglobulin binding protein mutant. The immunoglobulin binding protein mutant with high alkali stability provided by the invention is obtained by mutating in a Z structural domain of an amino acid sequence of staphylococcus aureus protein A, such as SEQ ID NO: 1, wherein the amino acid sequence of the Z structural domain is shown as SEQ ID NO: 1, and mutation sites comprise the 3rd amino acid, the 6th amino acid, the 9th amino acid, the 11th amino acid, the 23rd amino acid, the 25th amino acid, the 28th amino acid, the 32th amino acid, the 33rd amino acid, the 40th amino acid, the 42nd amino acid, the 43rd amino acid, the 44th amino acid, the 52nd amino acid and the 53rd amino acid. The prepared immunoglobulin binding protein mutant is prepared into affinity chromatography filler, the alkali resistance of the affinity chromatography filler and the affinity to an antibody can be remarkably improved, and the affinity chromatography filler can tolerate online cleaning of a 0.5-1.0 mol / L NaOH solution and has a good application prospect.

Immunoglobulin (Ig) binding proteins having one or more domains having highly hydrophobic amino acids with branched side chains (Iso, Leu, Val), or aromatic amino acids (Tyr, Phe, or Trp) corresponding to position 4 or 6 or 8 of the Ig binding protein of SEQ ID NO: 1 or functionally similar proteins are provided. The disclosed proteins have superior properties for highly efficient purification methods for antibodies (immunoglobulins), for example, the proteins have high binding capacity and high chemical stability. Also provided are affinity matrices that include the disclosed Ig binding proteins, uses of these Ig binding proteins and / or affinity matrices for affinity purification of immunoglobulins, and methods for affinity purification using the disclosed Ig binding proteins.

The invention belongs to the technical field of protein engineering, and particularly relates to an immunoglobulin binding protein mutant and application thereof. The immunoglobulin binding protein mutant provided by the invention is obtained by mutating in a C structural domain of an amino acid sequence of staphylococcus aureus protein A, such as SEQ ID NO: 1, wherein the amino acid sequence of the C structural domain is shown as SEQ ID NO: 1, and mutation sites comprise a first amino acid, a third amino acid, a sixth amino acid, a ninth amino acid, a tenth amino acid, an eleventh amino acid, a 23rd amino acid, a 25th amino acid, a 26th amino acid, a 28th amino acid, a 29th amino acid, a 32nd amino acid, a 43rd amino acid, a 44th amino acid, a 52nd amino acid and a 53rd amino acid. The prepared immunoglobulin binding protein mutant is prepared into affinity chromatography filler, the alkali resistance of the affinity chromatography filler and the affinity to an antibody can be remarkably improved, the affinity chromatography filler can tolerate online cleaning of a 0.5-1.0 mol / L NaOH solution, meanwhile, the antibody binding load reaches 73 g / L or above, and the affinity chromatography filler has a good application prospect.

The present invention relates to immunoglobulin (Ig) binding proteins comprising one or more domains having highly hydrophobic amino acids with branched side chains (Iso, Leu, Val), or aromatic amino acids (Tyr, Phe, or Trp) corresponding to position 4 or 6 or 8 of the Ig binding protein of SEQ ID NO: 1 or functionally similar proteins. The novel proteins have superior properties for highly efficient purification methods for antibodies (immunoglobulins), for example, the proteins have high binding capacity and high chemical stability. The invention further relates to affinity matrices comprising the Ig binding proteins of the invention. The invention also relates to a use of these Ig binding proteins or affinity matrices for affinity purification of immunoglobulins and to methods of affinity purification using the Ig binding proteins of the invention.

Provided herein are methods and compositions for purifying antibodies. Purification is achieved by increasing the binding capacity of protein A chromatography by covalent attachment of a protein A domain (E, D, A, B, C), or domain Z, or a functional variant thereof, to Drosophila melanogaster transcription factor Ultrabithorax (Ubx) materials. The compositions include fusion proteins containing Drosophila melanogaster transcription factor Ultrabithorax (Ubx) or a fragment thereof and an immunoglobulin binding protein. In some embodiments, the immunoglobulin binding protein is a protein A domain, a protein Z domain or a fragment thereof.

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 invention addresses the problem of revealing the mechanism of allergy development in which a bacterium of the family Lachnospiraceae, which is an enteric bacterium, including Ruminococcus gnavus (R. gnavus) is involved and of developing a means for preventing or treating allergies by intervening in the mechanism. The inventors of the present invention conducted an intensive study and, as a result, found that an Ibp protein from a bacterium of the family Lachnospiraceae is involved in development of allergies and showed that the above problem can be solved. That is, it is possible to prevent allergic reactions occurring in vivo by administration or induction of in vivo production of a substance that binds to the Ibp protein from a bacterium of the family Lachnospiraceae.

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 present disclosure relates to non-porous polymer particles having an average particle size of from 1 micron to 10 microns and functionalized with an immunoglobulin binding protein. The functionalized particles of the present disclosure can be used to purify a range of immunoglobulins having affinity for immunoglobulin binding proteins.

The application discloses Staphylococcus aureus specific nanobodies and a sandwich ELISA detection method and application thereof, and belongs to the technical field of foodborne pathogenic bacteria detection. The Staphylococcus aureus specific nanobodies provided by the application include at least one of Nb55, Nb90, Nb156 and 3Nb156. The application constructs a sandwich ELISA based on HRP-labeled monovalent or trivalent nanobodies to detect Staphylococcus aureus, which effectively avoids unnecessary interaction between the crystallizable fragment and the immunoglobulin binding protein, and is successfully used for detection in actual samples, has the advantages of time saving, low cost, sensitivity and the like, and has important reference value for wide promotion of nanobodies in the field of foodborne pathogenic bacteria detection.

The invention discloses an immunoglobulin binding protein, the immunoglobulin binding protein comprises a mutant of a Z structural domain of protein A, the mutant of the Z structural domain has good affinity and thermal stability, and a chromatography medium obtained by using the recombinant Protein A protein has higher binding capacity and alkali stability.

The present invention relates to novel ligands for affinity chromatography for the purification of antibodies. The novel ligands are immunoglobulin (Ig) binding proteins with superior properties for highly efficient purification methods for antibodies (immunoglobulins) in terms of extreme alkaline stability of the ligands combined with mild pH elution conditions for the antibodies. The invention further relates to affinity matrices comprising the novel ligands of the invention. The invention also relates to a use of these ligands or affinity matrices comprising these ligands for affinity purification of immunoglobulins and to methods of affinity purification.

To provide a method that enables efficient production of a polypeptide containing at least an immunoglobulin-binding domain of Protein L (FpL) originating from Finegoldia bacteria.SOLUTION: A production method comprises the step of culturing a recombinant Escherichia coli containing a polynucleotide encoding a polypeptide including at least an immunoglobulin-binding domain of FpL and expressing the polypeptide, and the step of purifying the polypeptide from a culture of the Escherichia coli, wherein the step includes a purification step using an anion-exchange chromatography and a purification step using a hydrophobic chromatography, wherein the purification step using the hydrophobic chromatography includes a step of equilibrating a hydrophobic chromatography column, a step of adding a sample containing the polypeptide to the column, and a step of recovering the polypeptide, wherein at least one of a solution for equilibrating the column and the sample contains 0.4 mol / L-1.1 mol / L ammonium sulfate.SELECTED DRAWING: Figure 10

The invention relates to a method for proteomic analysis and a substrate prepared for the method. The substrate is prepared with immobilized antibodies using the electrospray deposition method, where a planar conductive plate is used as the substrate, onto which ions of immunoglobulin-binding protein are deposited by electrospray, then at least one antibody with affinity for the target antigen is dispensed onto the substrate with immobilized immunoglobulin-binding protein, which is anchored via a non-covalent affinity interaction with the immobilized immunoglobulin-binding protein. Subsequently, a sample containing the antigen is dispensed onto the substrate with the immobilized immunoglobulin-binding protein and bound antibody, and the prepared substrate is incubated. After incubation of the substrate, sample residues are removed, an analyte with an antigen is chemically reduced or eluted from the substrate and cleaved with trypsin, an analyte with an antigen is desalted, and the sample is analysed using a proteomic method.

The application discloses a kind of recombinant ProteinA protein and the preparation method of affinity chromatography medium, the protein is the mutant of parent immunoglobulin binding protein defined in SEQ ID NO2;The preparation method of the affinity chromatography medium includes the following steps: S1, the gene of recombinant ProteinA protein is synthesized, S2, respectively constructs expression vector using the gene synthesized in the S1, S3, is expressed and purified to obtain the recombinant ProteinA solution of sequence corresponding SEQ ID, S4, using the recombinant ProteinA preparation obtains affinity chromatography medium.Beneficial effects: the application greatly improves the chemical stability of ProteinA in lye by redesigning amino acid sequence, to provide a ProteinA with specific binding effect for antibody, it has good chemical stability under alkaline condition, the binding capacity of recombinant ProteinA affinity chromatography medium is significantly improved, can tolerate 0.5-1.0M NaOH in situ cleaning, IgG binding capacity 60-90mg / mL.

The present invention relates to novel ligands for affinity chromatography, particularly for the purification of antibodies. The novel ligands are immunoglobulin (Ig)-binding proteins with excellent properties for highly efficient purification methods for antibodies (immunoglobulins). The invention further relates to affinity matrices comprising the ligands of the invention. The invention also relates to the use of these Ig-binding proteins or affinity matrices for the affinity purification of immunoglobulins, and to methods of affinity purification using the Ig-binding proteins of the invention.

Improved sample preparation methods for detecting and / or quantifying host cell proteins in a sample are provided. The methods include contacting the sample with a solid support comprising an immunoglobulin binding protein at a pH of about 8-10 to produce a sample comprising an antibody or antibody fragment bound to the solid support. The method further comprises contacting the sample comprising the antibody or antibody fragment bound to the solid support with a protease agent to produce partially digested antibodies and target proteins, and separating the sample into fractions comprising a first fraction comprising the antibody or antibody fragment bound to the solid support and a second fraction comprising the antibody or antibody fragment bound to the solid support and a third fraction comprising the antibody or antibody fragment bound to the solid support. The second fraction comprises a supernatant comprising a partially digested target protein. The method further includes treating the supernatant and detecting one or more target proteins, such as using mass spectrometry. Compositions and kits for detecting host cell proteins are also provided.