幽门螺杆菌VacA重组蛋白表达、纯化及鉴定

目的研究幽门螺杆菌空泡毒素（VacA）编码基因在大肠埃希菌中的表达及纯化重组蛋白的抗原性。方法将PET32a-vacA-E.coli BE21（DE3）工程菌株常规培养，碱裂解法小量提取重组质粒DNA，琼脂糖凝胶电泳进行酶切鉴定，基因测序法进行插入基因序列分析。重组蛋白采用IPTG诱导表达，镍亲和层析原理提纯，ELISA法检测其抗原性。结果经酶切鉴定表明，插入的基因片段全长约2240bp，测序分析及与Genebank比较，可以肯定插入片段为vacA基因，ELISA法检测重组蛋白具有良好的抗原性。结论VacA重组蛋白在大肠埃希菌中成功表达，重组蛋白具有良好的抗原性。

Expression,purification and identification of the recombinant VacA of Helicobacter pylori

Objective To express the VacA recombinant protein of Helicobacter pylori(H.pylori) in E.coli and identify the antigenity of the purified protein.Methods The pET32a-vacA-E.coli BL21(DE3) was cultivated in LB liquid culture medium.The pET32a recombinanted plasmid was extracted and purified by alkaline method and analysed by restriction endonuclease of EcoR I,Xho I enzyme,vacA gene was analysed by sequencing.The recombination protein expression induced by IPTG and purified by 6Xhis marked Ni-TED~(TM) kit.The antigenicity of the protein was analysed by ELISA.Results The inserted gene was vacA and it had about(2 240) bp.The recombinant VacA was expressed in E.coli.ELISA method examination shown that the recombianant protein had good antigenicity.Conclusion The recombinant protein could be expressed successfully in E.coli BL21(DE3) and it had good antigenicity.