穿膜肽HIV-TAT与呼吸道合胞病毒G蛋白片段G1及CTL表位融合蛋白的表达及纯化

目的在大肠杆菌中表达含穿膜肽HIV-TAT与呼吸道合胞病毒(RSV)G蛋白片段G1及CTL表位的融合蛋白,并进行纯化。方法以质粒pET-G1F/M2为模板,扩增含TAT、RSVG蛋白片段G1和CTL表位F/M2的融合基因片段,与原核表达质粒pET-His连接,构建融合表达质粒pET-TAT-G1F/M2,转化E.coli BL21(DE3)plysS进行诱导表达,采用Ni2+螯合亲和层析法纯化经尿素变性的包涵体,梯度透析复性纯化的目的蛋白,并进行Westernblot鉴定。结果在E.coli中可高效表达重组蛋白TAT-G1F/M2,表达量占菌体总蛋白的30%以上,目的蛋白主要存在于包涵体中。经变性、纯化、复性可获得高纯度(>95%)特异性的TAT-G1F/M2蛋白。结论已在大肠杆菌中成功表达了融合蛋白TAT-G1F/M2,为进一步进行RSV体内体外免疫学研究奠定了基础。

Expression and Purification of Fusion Protein Containing Cell-penetrating Peptide HIV-TAT as well as Glycoprotein G1 and CTL Epitope of Respiratory Syncytial Virus

Objective To express the fusion protein containing Cell-penetrating peptide HIV-TAT as well as the glycoprotein G1 and CTL epitope of respiratory syncytial virus(RSV)in E.coli and purify the expressed product.Methods Amplify the fusion gene encoding HIV-TAT as well as G1 protein and CTL epitope F / M2 of RSV using plasmid pET-G1F / M2 as a template and insert into prokaryotic expression vector pET-His.Transform the constructed recombinant plasmid pET-TAT-G1F / M2 to E.coli BL21(DE3)plysS for expression under induction of IPTG.The expressed product in a form of inclusion body was denaturalized with urea,purified by nickel ion chelate affinity chromatography,renaturalized by gradient dialysis and identified by Western blot.Results The recombinant fusion protein TAT-G1F / M2 expressed in E.coli mainly existed in inclusion body and contained more than 30% of total somatic protein.After denaturalization,purification and renaturalization,the expressed protein reached a purity of more than 95%.Conclusion Fusion protein TAT-G1F / M2 was successfully expressed in E.coli,which laid a foundation of in vitro and in vivo im-munological study on RSV.