Optimization of Procedure for Expression and Purification of Recombinant Human Fibroblast Growth Factor-21

Objective To optimize the condition for fermentation of recombinant E. coli with fusion gene of SUMO and human fibroblast growth factor-21 (SUMO-rhFGF-21)as well as the procedure for purification of target protein. Methods The temperature and time for induction as well as concentration of inducer of recombinant E. coli was optimized. The recombinant E. coli was fermented under the optimal condition, and the lysate of bacteria was purified by ion exchange, nickel ion affinity and molecular sieve chromatography. The purified target protein was determined for purity by SDS-PAGE and HPLC. Results The optimal temperature and time for induction of recombinant E. coli were 37℃ and 4 h respectively, while the optimal concentration of IPTG as an inducer was 0. 5 mmol / L. The expression level of target protein reached a peak value of 20. 5% under the optimal condition. The yield of bacteria after fermentation reached 66 g / L, and the expression level of target protein was 20. 2%. After purification, the purity of target protein was more than 96%. Conclusion The procedure for expression and purification of rhFGF-21 was optimized, which laid a foundation of developing rhFGF-21 as a novel drug.