关键词: 原核表达, BHMT基因, 条件优化

Abstract: Betaine-homocysteine methyl transferase (BHMT), which is a methyl-metabolizing enzyme , can catalyze methyl of betaine shifting to homocysteine, forming methionine. In this study, pET30a-SsBHMT was expressed in Escherichia coli. The strains, IPTG concentrations and induction time were optimized. The results showed that the expressed protein mainly existed in the form of inclusion bodies. After optimization, the target protein expression levels were increased both in supernatant and precipitate, but mainly in the form of inclusion bodies. In the strain of ER2566, the expression level of recombinant protein was high when induced for 10 h by 0.4 mmol/L of IPTG at 37℃. The results laid a foundation for further studies on the protein purification and antibodies preparation.

Key words: prokaryotic expression, BHMT gene, condition optimization