HPV18E6基因的原核克隆及表达

目的:构建pET32a(+)HPV18E6原核表达质粒并优化其表达条件,探讨喉癌组织中HPV18E6蛋白的表达及意义.方法:应用基因重组技术,构建pET32a(+)与HPV18E6的原核表达重组质粒,采用PCR方法扩增HPV18E6基因,经BamHⅠ和Hind Ⅲ双酶切后插入相同酶切pET32a(+)载体,转化JM109感受态细胞并进行阳性克隆筛选,用限制性内切酶酶切和核酸序列检测方法鉴定重组质粒DNA,将其转入宿主菌E.coli BL21(DE3),用IPTG对重组质粒进行诱导表达,SDS-PAGE及Western blot方法鉴定表达蛋白的分子质量及特异性.结果:成功构建了原核表达质粒Pet32/HPV18E6, 限制性内切酶酶切和核酸序列检测证实重组质粒中插入的是目的基因,其DNA大小、方向、插入位点和阅读框架均正确;HPV18E6蛋白得到高效原核表达,表达HPV18E6的工程菌BL21(DE3)的最佳诱导温度是37 ℃,诱导剂IPTG的浓度为1 mmol/L. 结论:HPV18E6融合蛋白的表达为进一步深入研究HPV18E6蛋白的生物学特性及其致细胞转化的作用机制奠定了基础.

Cloning and Expression of HPV18 E6 Gene

Objective: To express the protein of HPV18E6 based on pET-32a(+) at high level and study the expression and significance of HPV18E6 proteins in laryngeal carcinoma. Methods: The HPV18E6 gene was amplified by PCR and cloned into pET-32a(+). The amplified fragment was inserted into the plasmid pET32a (+) that was digested with BamHⅠand Hind Ⅲ. The recombinant plasmid pET32/E6 was transformed into E.coli JM109 which was selected with ampicillin. The recombinant plasmids were successfully introduced into E.coli BL21(DE 3) and were induced by IPTG. SDS-PAGE and Western blot analysis were used to detect the confusion protein. Finally, the optimization of expression conditions, such as temperature, concentration of IPTG, was studied. Results: The recombinant plasmids were identified and confirmed with enzyme digestion and sequencing. The BL21(DE3) transformed recombinant plasmid pET32/E6 had expressed HPV18E6 recombinant protein effectively. The optimum conditions of expression were 37 ℃, 1 mmol/L IPTG. Conclusion:Prokaryotic expression vector pET-32a(+)-HPV18E6 was successfully constructed. The high-level expression of HPV18E6 was achieved in E.coli BL21(DE3).