37 results about "Recombination Protein A" patented technology

The invention relates to a method for separating and purifying a recombinant protein A, belongs to a protein separation and purification technology in the technical field of bioengineering and provides a method for separating and purifying a recombinant protein A by combining heating treatment and activated carbon adsorption. The purity of the recombinant protein A obtained by the method through separation and purification can be up to 95% or above, the final protein A recovery rate can be up to 60% or above, the endotoxin content in the recovered protein solution is less than 10 EU / mg, and the endotoxin content can be reduced to 1 EU / mg or below if hydrophobic chromatography is further included in the purification method. The method has the advantages of low cost and high recovery rate, is convenient to realize industrial production and provides a feasible route for the large-scale production of the recombinant protein A.

The invention relates to the technical field of biological engineering. The B structure domain gene monomer of protein A is optimized according to the preference of a colon bacillus colon, six series bodies are constructed and inserted into a thermally induced colon bacillus vector pBV220, and a colon bacillus expression vector containing the gene and a converted colon bacillus DH5alpha recombination strain thereof are constructed. And a method for producing the recombination protein A using the strain is also provided. The total soluble bacterial protein amount of the soluble recombination protein A produced by the strain can be more than 80 percent, and the recombination protein A can be purified to over 95% just by subsequent nickel ion chelate chromatography and molecular sieve column chromatography. Moreover, the protein has the advantages of high expression amount, low cost, easy purification and the like. A recombination protein A affinity stuffing prepared by using the protein has the advantages of high human IgG absorption capacity, low proA dropping and the like. The invention provides a practical and feasible approach to obtain the recombination protein A with high quality and low price as an antibody (medicine) purifying medium.

The present invention provides a recombinant protein A gene, whose nucleotide acid sequence is shown in SEQ ID NO.1, and the recombinant protein A coded by the gene. The present invention also provides recombinant expression carrier PET32a-P for expressing the recombinant protein A gene, E. coli BL21 / DE3 converted by the gene, and the method for preparing recombinant protein A. Recombinant protein A can be used for antibody detection, separation and purification, and can constitute affinity chromatography medium together with chromatography medium carrier. Recombinant protein A has such advantages as high protein combination specificity, high affinity and high purification efficiency, and has obviously increased dynamic adsorption capacity compared with commercialized Protein A Sepharose 4 Fast Flow.

The invention relates to an immunochromatographic test paper for detecting human immunodeficiency virus antibodies and a preparation method thereof, belonging to the field of reagents for detecting human immunodeficiency virus antibodies. The immunochromatographic test paper comprises a sample pad, a nitrocellulose membrane and a water absorption pad which are sequentially connected, wherein the sample pad contains a superparamagnetic composite particle labeled recombinant protein A; the nitrocellulose membrane is coated with a detection line and a quality control line which are mutually separate; the detection line contains a human immunodeficiency virus recombinant antigen; the quality control line contains an anti-recombinant protein A antibody which can be specifically combined with the recombinant protein A; and the human immunodeficiency virus is human immunodeficiency virus Type 1+2. The immunochromatographic test paper has the advantages of high sensitivity and high specificity, is quick and convenient, and can implement objective determination.

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.