IgG1 Fc monomer and application thereof

Abstract

The invention belongs to the technical field of biology, and particularly relates to an IgG1Fc monomer and a preparation method and application thereof. In accordance with the sequence of a novel IgG1Fc monomer reformed in an antibody IgG1 constant region, through an antibody engineering technique, a human antibody IgG1 constant region Fc is reformed, so that an Fc dipolymer becomes an Fc monomer,an FcRn combination function is maintained, and an extremely low irrelevant protein non-specific combination characteristic is achieved; main features of the Fc monomer lie in that the Fc monomer hasmutation at positions of T366, L368, P395 and K409 in a CH3 region of the antibody constant region, has high-efficiency expression in prokaryotic cells, can use combination of a pH dependent specialcombination mode with FcRn, and has extremely low nonspecific combination characteristics. Through the novel Fc monomer, the IgG1Fc monomer can fuse or couple with various protein, polypeptide, micromolecules, nucleic acid and the like for different target points, so that fused or coupled molecules have the characteristic of combining pH dependence with FcRn.

Description

technical field [0001] The invention belongs to the field of biotechnology, and specifically relates to an IgG1 Fc monomer, a preparation method thereof, and an application thereof. Background technique [0002] Research has disclosed that there are currently three main long-acting technologies for protein drugs: PEG (polyethylene glycol) modification technology, HSA (human serum albumin) fusion technology, and Fc (human antibody Fc region) fusion technology. The three technologies all have their own weaknesses, among which the common key disadvantage is that there is a significant increase in the molecular weight of the fused or modified protein drug, and it often significantly reduces the yield and clinical efficacy of the fused protein drug; for example, human antibody The constant region Fc is a homodimer, its own molecular weight is already 60kDa, and the fusion protein can only be in the form of dimerization, which makes the molecular weight of the fusion protein often...

AI Technical Summary

Problems solved by technology

In the previous study of the present invention, a new method of multiple functional screening was used to transform the human IgG1 Fc region, and 1 billion (1 billion 9 ) different Fc mutant molecules were screened for druggability, FcRn binding activity, etc., and an Fc monomer molecule (mFc) was constructed. Protein A / G binding performance, and has the excellent characteristics of highly soluble expression in Escherichia coli, and the half-life in animals can be as long as about two days; then, during the research process, it was found that it has very strong non-specific binding properties, This property may make mFc non-specifically bind unrelated proteins when used in vivo, greatly limiting its clinical use space

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