EXPRESSION IN ESCHERICHIA-COLI AND PURIFICATION OF HUMAN THROMBOPOIETIN

Human thrombopoietin (TPO) has been successfully overexpressed in Esch erichia coli, with an expression level of about 12% of total cellular protein, The full-length TPO gene was subcloned into the prokaryotic e xpression vector pKK233-2 under the control of the inducible tac promo ter, The recombinant protein was produced mainly in the form of inclus ion body, By efficient renaturation and one-step purification, the rec ombinant protein was purified to homogeneity, The specific activity an d yield of recombinant TPO can reach 2 x 10(4) units/mg and 2 mg/g of wet E. coli cells respectively.