幽门螺杆菌Lpp20融合蛋白的表达、标签切除及鉴定

Expression,Tag Cleavage and Identification of Lpp20 Fusion Protein of Helicobacter pylori

目的:利用GST融合基因表达系统表达Lpp20-GST融合蛋白,并利用凝血酶切除GST标签。方法:IPTG诱导重组质粒Lpp20/pGEX-4T-1在大肠杆菌BL21(DE3)中表达,菌体经反复冻融、溶菌酶裂解及超声破菌后,发现Lpp20-GST融合蛋白以部分可溶性的形式表达。采用GST蛋白纯化系统对其纯化,得到Lpp20-GST融合蛋白,再用凝血酶进行GST标签的切除,所得产物进行Western Blot鉴定。结果:高效表达出Lpp20-GST融合蛋白的相对分子质量约4.5kDa,凝血酶成功切除了GST标签,Western Blot证实Lpp20蛋白能被鼠抗Lpp20单克隆抗体识别。结论:成功表达和纯化了重组Lpp20蛋白,为深入研究Lpp20的功能奠定了基础。

Objective：To express Lpp20-GST fusion protein by GST gene expression system and cleave GST-tag using thrombin.Method：The recombinant Lpp20/pGEX4T-1 plasmid was induced in E.coli BL21（DE3） by IPTG.The bacterial sediment was lysed by repeating freezing and thawing,lysozyme lysis and ultrasonication.Lpp20-GST fusion protein was purified by GST protein purification system and cleaved the GST-tag using thrombin.Then Lpp20 was identified by anti-Lpp20 monoclonal antibody using Western Blot.Result：The fusion Lpp20-GST was partly expressed in soluble form with relative molecular mass of 4.5kDa.After cleavage of GST tag,Lpp20 protein was recognized by mouse anti-Lpp20 monoclonal antibody by Western Blot.Conclusion：The recombinant Lpp20 is successfully expressed and purified,which lay a foundation for further study on function of Lpp20.