幽门螺杆菌细胞毒素相关蛋白CagA原核表达载体的构建及诱导表达

Construction and Expression of Helicobacter Pylori Virulence Factor CagA Prokaryotic Expression Vector

目的构建幽门螺杆菌细胞毒素相关蛋白CagA的原核表达载体并诱导表达，为进一步利用此表达载体研究中药的抗幽门螺杆菌的机制提供物质条件。方法以幽门螺杆菌基因组为模板，通过PCR体外扩增cagA基因，将cagA基因插入带绿色荧光蛋白标签的原核表达载体PE33gb，利用含氨苄青霉素的LB平皿筛选阳性克隆子，以IPTG诱导含重组子PET34b—cagA的E．coliD历d表达CagA蛋白。结果PCR扩增出3400bp的DNA片段，SDS—PAGE电泳显示出有分子量128kD的蛋白条带。结论成功克隆并表达了幽门螺杆菌毒力因子CagA，为后续研究中药抗幽门螺杆菌奠定了物质基础。

Objective To construct the prokaryotic expression vector PET34b-cagA of H. pylori virulence factor CagA and induce the expression in order to further study the mechanism of Chinese medicines against H. pyloriMethods cagA gene of H. pylori was amplified by PCR. the cagA gene was inserted into expression vector PET34b, and LB plate containing ampicillin was used to screen positive clones. E. coli DH5a containing the positive recombinant PET34b-cagA was induced by IFFG to express CagA protein. Results 3 400 bp DNA fragment was amplified by PCR, and a 128 kDa protein band was displayed by SDS-PAGE eleetrophoresis. Conclusion The H. pylori virulence factor CagA was successfully cloned and expressed, which may provide a foundation for the study on Chinese medicines against H. pylori.