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凋亡抑制蛋白Livin 两种异构体原核表达载体的构建及融合表达

Construction of Prokaryotic Expression Vectors for Livin Alpha and Livin Beta

  • 摘要: 目的 构建凋亡抑制蛋白Livin两种异构体(Livinα和β)的原核细胞表达载体pET32a(+)-livinα和pET32a(+)-livinβ。方法 设计合成扩增Livin基因异构体全长cDNA序列的特异性PCR引物,以Hela细胞总RNA为模板,RT-PCR获得Livin基因异构体全长cDNA序列,用限制性内切酶BamHⅠ和HandⅢ双酶切取所需目的片段,并插入原核表达载体pET32a(+)的多克隆位点,经酶切、PCR鉴定,并经过测序证实后,构建成为Livin基因异构体表达载体(pET32a(+)-livinα、β)。将重组质粒转入表达菌株BL21,诱导表达收集菌液,超声碎菌,取其上清和沉淀分别进行SDS-PAGE电泳。结果 成功获得Livinα和β全长cDNA序列,并克隆到原核表达载体pET32a(+)上;成功获得大小为55kd左右的融合蛋白。结论 Livin基因两种异构体原核表达载体的构建及其融合蛋白的制备,为进一步研究Livin异构体功能及在肿瘤细胞中的抗凋亡效应奠定了基础。此蛋白也可用于进一步抗体制备、免疫鉴定和诊断等研究。

     

    Abstract: Objective  To const ruct prokaryotic expression vectors for Livinαand Livinβand to obtained the fusion protein of p ET32a ( + )-livinα and p ET32a ( + )2livinβ. Methods  Total RNA of Hela cell was extracted. The full-length cDNA of Livin isoforms was gained by RT-PCR. Then inserted into p ET32a ( + ) vector and const ructed the recombinant plasmids p ET32a ( + )2livinα/ DH5α and p ET32a ( + ) / livinβ/DH5α, sequencing was performed to guarantee correct sequence insertion for the isoforms Livinα and Livinβ. Reconst ructed the recombinant plasmids p ET32a ( + )-livinα/ BL21 and p ET32a ( + ) / livinβ/BL21, the p ET32a ( + )-livinα/ BL21 and p ET32a ( + )-livinβ/ BL21 plasmids was induced af ter 4. 5 hours by IPTG, and the value of A600nmwas 0. 6 in LB medium. Expression of the p ET32a ( + )-livinα/ BL21 and p ET32a ( + )-livinβ/ BL21 were analyzed by SDS-PA GE . Results  Full-length cDNA of Livinαand Livinβ was cloned respectively and subcloned into p ET32a ( + ) successfully. Fusion protein of positive recombinants were gained by p ET32a ( + ) prokaryotic expression system. Conclusion  The construction of prokaryotic expression vector for Livinαand Livinβand validation of expression in cells provide basis for further research on functions of Livinαand Livinβand their anti-apoptosis effect in cancer cell.

     

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