Small-molecular affinity peptide and application thereof

Abstract

The invention relates to the field of molecular biology and in particular relates to a small-molecular peptide and an application thereof. The amino acid sequence of the small-molecular affinity peptide disclosed by the invention is as shown in any one of SEQ (sequence) ID (identity) No. 1-18. The small-molecular affinity peptide disclosed by the invention can be combined with an Fc fragment of human immunoglobulin IgG. Efficient, safe and economic IgG separation and purification can be realized by adopting the small-molecular affinity peptide as an affinity ligand.

Description

Technical field [0001] The present invention relates to the field of molecular biology. Specifically, the present invention relates to a small molecule peptide and its application. Background technique [0002] Immunoglobulin IgG, that is, an antibody is a special protein molecule, used as in vitro diagnostic reagents, disease treatment drugs, immunoaffinity chromatography ligands, etc. It is widely used in life science research, biotechnology and medicine. Applications. [0003] At present, the separation and purification of IgG mostly uses the natural affinity ligand ProteinA / G of the antibody. Because ProteinA / G has the ability to specifically recognize the Fc fragment of the antibody, the protein A / G affinity chromatography is used to purify the antibody, and the purity of the product obtained is Higher. However, because ProteinA / G is also an active biological substance, there are some problems in the separation of ProteinA / G: [0004] 1) Expensive: Because the protein A ligan...

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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 ProteinA / G

[0013] Therefore, the current separation and purification of IgG lacks an efficient, safe and economical affinity ligand

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