Method for preparing human chorion gonadotrophic hormone beta subunit

Abstract

The invention belonging to the biopharmaceutical field relates to a high efficient preparation method for human chorionic gonadotrophin Beta subunit (hCG Beta), including the steps as follows: eukaryon expression vector is adopted to construct the eukaryon expression vector containing 6his purifying label and human chorionic gonadotrophin Beta subunit; a mammal expression system is used as an expression host to obtain stable and efficiently and accurately expressed human chorionic gonadotrophin Beta subunit protein after in vitro expression, identification and purification. The invention is of high value in providing hCG Beta with biological activity; moreover, the obtained hCG Beta can be used in biological medicine development and in monoclonal antibody and polyclonal antibody preparation as immunogen immune animal, thereby completely solving the problem of hCG Beta shortage.

Description

technical field [0001] The invention belongs to the field of biopharmaceuticals, and relates to a high-efficiency preparation method of human chorionic gonadotropin beta subunit (hCGbeta). Background technique [0002] Natural hCG is a glycoprotein hormone composed of two subunits α and β. They are held together by ionic and hydrophobic bonds. The α subunit is a 92-amino acid glycopeptide whose amino acid sequence is identical to that of some pituitary glycoprotein hormone subunits, such as LH, FSH, and TSH. The β subunit is a glycopeptide of 145 amino acids, stabilized by 6 disulfide bonds. There are N-type glycosylation at the 13th and 30th Asn residues, and 4 O-type glycosylations at the 121-145th Ser residues at the C-terminal; the glycoprotein hormone β subunit has unique biological activity and can Promote follicle maturation, thyroid stimulation and testicular Leydig cell activity. The source of hCGβ natural products is limited, and the chemical synthesis is expen...

AI Technical Summary

Problems solved by technology

The prokaryotic expression system is easy to operate, high yield, short cycle time and low cost, but there are very few reports on the expression of hCGβ using this system, which may be because: ① Escherichia coli has no sugar chain processing system, cannot synthesize glycoproteins, and non-glycosylated expression is possible It will affect the biological activity and immunogenicity of hCGβ; ②There are six pairs of disulfide bonds in the hCGβ molecule, but the E. coli cells cannot form or form wrong disulfide bonds, so the protein cannot be folded correctly to form a certain spatial conformation, Complex renaturation in vitro is required to obtain biologically active proteins; however, if there are more than three pairs of disulfide bonds, the renaturation rate is almost reduced to zero, so it may not be necessary to express hCGβ in Escherichia coli in view of the above considerations; there have been scholars Using this system to express hCGβ, the non-glycosylated expression product is not a true self-protein, and its immunogenicity and related toxicology studies are still in progress

[0004] The yeast expression system has a disulfide bond formation and sugar chain processing system, but the oligosaccharide groups of the expression products are different from those expressed by mammalian cells, and the terminals are mostly mannose, N-glycolylneuraminic acid and galactose, which will appear Hyperglycosylation, which affects the biological activity of the protein and may generate new antigenicity and cause hypersensitivity

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