人乳头瘤病毒18型L1蛋白在大肠埃希菌中的可溶性表达及病毒样颗粒的形成

目的利用大肠埃希菌系统可溶性表达人乳头瘤病毒18型(HPV18)L1蛋白,纯化和重组装获得HPV18病毒样颗粒(VLPs),为进一步研制HPV18基因工程疫苗奠定基础。方法首先按大肠埃希菌密码子偏好进行HPV18L1全基因合成,经PCR扩增出截短的HPV18L1基因,构建重组表达载体PET30a-L1,通过优化表达在大肠埃希菌BL21中可溶性表达L1蛋白,其次采用硫酸铵沉淀、离子交换层析、疏水层析后,获得高纯度的的L1蛋白,再通过解聚和重聚获得VLPs。结果全基因优化并截短的HPV18L1蛋白在大肠埃希菌系统中以可溶形式表达,纯化后的蛋白纯度达到90%以上,电镜下观察到直径为60 nm的VLPs颗粒。结论利用大肠埃希菌系统可溶性表达非融合HPV18L1蛋白,并获得均一的VLPs颗粒,为疫苗的开发奠定基础。

Soluble expression of HPV type 18 L1 protein from Escherichia coli and formation of virus-like particles

Objective To express the major structural protein L1 of Human papillomavirus type 18 （HPV18） as asoluble form in E.coli BL21.L1 protein was purified and re-assembled into virus-like particles （VLPs） in vitro.This laid a foun-dation of further development of genetically engineered vaccines .Methods Full-length gene of HPV type 18 L1 was syn-thesized according to the codon bias of E.coli.The truncated L1 gene was amplified by PCR .The amplified L1 fragment was inserted in toan expression vector PET 30a and was expressed in a form of soluble protein in E.coli by an expression optimization.Then L1 protein was purified by ammonium sulfate precipitation , ion-exchange chromatography and hydropho-bic interaction chromatography .L1 was subjected to self-assembly VLPs with disassembly and reassembly .Results HPV type 18 L1 protein with a full-length gene optimization and truncated mode was expressed in a soluble form in E.coli sys-tem.The purity of purified L1 protein is more than 90%.Observation by transmission electronic microscopy showed that the VLPs formed in a round shape with a diameter about 60 nm.Conclusion Nufusion HPV L1 protein was expressed as asolu-ble form from E.coli and subjected to form uniform VLPs , which may provide an useful tool for development of HPV vac-cines.