Small molecular antibody affinity peptide and application thereof

Abstract

The invention relates to the field of molecular biology, in particular to a small molecular antibody affinity peptide with high antibody selectivity and application. The amino acid sequence of the small molecular antibody affinity peptide disclosed by the invention is shown as any of SEQ ID NO.1 to SEQ ID NO.54. The small molecular antibody affinity peptide according to the invention is combined with the Fc segment of immunoglobulin G (IgG), and is not combined with human serum albumin (HAS). When the small molecular antibody affinity peptide disclosed by the invention is taken as an affinity ligand, efficient, safe and economical IgG separation and purification can be realized.

Description

technical field [0001] The invention relates to the field of molecular biology, in particular, the invention relates to an antibody high-selectivity small molecule antibody affinity peptide and its application. Background technique [0002] Immunoglobulin IgG, that is, an antibody is a special protein molecule, which is used as a reagent for in vitro diagnosis, a drug for treating diseases, a ligand for immunoaffinity chromatography, etc., and has a wide range of applications in the fields of life science research, biotechnology and medicine. Applications. [0003] At present, the separation and purification of IgG mostly use the natural affinity ligand Protein A / G of the antibody. Due to the ability of Protein A / G to specifically recognize the Fc fragment of the antibody, the protein A / G affinity chromatography is used to purify the antibody, and the obtained The purity of the product is high. However, since Protein A / G is also an active biological substance, there are al...

AI Technical Summary

Problems solved by technology

[0004] 1) Expensive: Because the protein A ligand needs to be produced and purified by genetic engineering, the production cost is high, and its price reaches $10,000 / liter of affinity medium;

[0005] 2) There is a lack of effective cleaning methods. Since protein A is unstable in an alkaline environment, general sodium hydroxide in-situ cleaning methods cannot be used;

[0006] 3) Since the ligand is also a protein, it is easily hydrolyzed by the protease present in the raw material solution, thereby reducing the separation effect;

[0008] 5) The ligand is easy to fall off, and the fallen protein A will cause human immune response and has been clinically proven to be toxic to the human body;

[0009] 6) The elution pH is low (pH2-3), which can easily cause some antibodies to be inactivated or aggregated. It is often necessary to collect the product while neutralizing it, which increases the complexity of the operation

[0012] 2) Poor affinity: The ligand affinity of current small molecule compounds is usually lower than that of Protein A / G

[0013] 3) Poor selectivity: the current small molecule compound ligands will also bind to the main separation impurity HAS (human serum albumin) while binding to IgG

[0014] Therefore, the current separation and purification of IgG lacks an efficient, safe and economical affinity ligand

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