10 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.

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 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 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.