人乙醛脱氢酶2的原核表达及条件的优化

通过双酶切、连接转化等方法将人乙醛脱氢酶2(ALDH2)基因克隆至载体pGEX-4T-1上,构建原核表达重组质粒pGEX-4T-1-ALDH2。重组质粒转化至E.coli BL21(DE3)后经IPTG诱导,SDS-PAGE分析表明目的蛋白得到大量表达。由于此载体本身带有融合蛋白标签GST(谷胱甘肽转移酶),所以得到了部分可溶性的目的蛋白。通过对表达条件进行探讨,发现在28℃下,以终浓度0.1mmol·L-1的IPTG诱导表达10h,可溶性的目的蛋白约占总蛋白的25%。表明,融合蛋白标签GST及较低的诱导温度有利于提高人乙醛脱氢酶2基因在大肠杆菌内的可溶性表达。

Prokaryotic Expression and Optimization of Expression Conditions for Human Acetaldehyde Dehydrogenase 2

The human acetaldehyde dehydrogenase 2（ALDH2） gene was cloned into prokaryotic expression vector pGEX-4T-1 with fusion protein tag GST to construct prokaryotic expression recombinant plasmid pGEX- 4T-1-ALDH2. The recombinant plasmid was transformed into E. coli EL21 （DE3）. After being induced by IPTG,expression of the purpose protein was verified by SDS-PAGE analysis, and through optimizing the expression conditions（0.1 mmol· L^-1 IPTG, 28℃, 10 h）, the purpose protein present in supernatant achieved 25% of that in pellet of the bacterial lysate because of the fusion protein tag GST. It showed that the fusion protein tag GST and low temperature could improve soluble expression of ALDH2 in Escherichia coli.