苏云金芽胞杆菌cry2Ac4基因在大肠杆菌中的表达

Expression of cry2Ac4 Gene from Bacillus thuringiensis in Escherichia coli

在大肠杆菌中表达苏云金芽胞杆菌(Bacillus thuringiensis,简称Bt)cry2Ac4基因;笔者以含有BtWB9菌株cry2Ac4基因的质粒pMD2Ac为模板,利用cry2Ac4基因的特异引物对(ET-F/ET-R)扩增获得该基因,进而将cry2Ac4基因与pET-29a原核表达载体连接;成功构建了重组表达载体并转化大肠杆菌JM109,从阳性转化子中提取重组表达质粒pET-29a-cry2Ac4,再转化大肠杆菌BL21(DE3)pLysS,经IPTG诱导后,对诱导表达产物进行了SDS-PAGE检测;cry2Ac4基因编码的约70kDa蛋白在大肠杆菌中得到了高效表达。

Expression of cry2Ac4 Gene from Bacillus thuringiensis （Bt） in Escherichia coli. The cry2Ac4 gene from Bt WB9 was amplified by PCR using plasmid DNA of pMD2Ac as the template and ET-F/ET-R as the specific primers. Subsequently, the amplified fragment of cry2Ac4 gene was inserted into a prokaryotic expression vector pET-29a. A recombinant expression vector pET-29a-cry2Ac4 was constructed and then transformed into Escherichia coli JM109. The plasmid of pET-29a-cry2Ac4 was recovered from the positive transformant, and further transformed into E. coli BL21 （DE3） pLysS to express the Cry2Ac4 protein by the induction of IPTG. SDS-PAGE showed that the molecular weight of the expressed product was about 70kDa.