洋葱糖基转移酶UGT73G1在大肠杆菌中的可溶性表达与纯化

Escherichia coli is the preferred host of heterologous protein overexpression. Soluble expression of plant-derived genes in E.coli is the important prerequisite of obtaining a large number of enzymes and synthesizing natural products by biotransformation. In this study, glycosyltransferase UGT73G1 from Allium cepa was recombinant expressed in E.coli. Soluble expression of UGT73G1 was increased by imported the chaperone plasmid pG-KJE8 and added the histidine-tag at C-terminal. The recombinant enzyme was purified. In contrasted, the specific activity of recombinant strain which added the histidine-tag at C-terminal was three times of the original recombinant strain. Further more, the specific activity of recombinant strain which added the histidine-tag at C-terminal and imported the chaperone plasmid pG-KJE8 was four times of the original recombinant strain. It is shown that fusion expression of histidine-tag at C-terminal can effectively improve the soluble expression of UGT73G1. This strategy will provide a reference for glycosyltransferase gene prokaryotic expression.