戊型肝炎病毒基因 ORF3编码蛋白在大肠杆菌中的表达及鉴定

实验以两种不同的表达策略构建了两个以大肠杆菌DE3为宿主的原核表达载体，由T7启动子启动外源基因的转录，在诱导剂IPTG诱导下成功地进行了戊肝病毒ORF3蛋白的原核表达。并通过SDS-聚丙烯酰胺凝胶电泳、免疫印迹、竞争抑制法酶联免疫等一系列实验对两种表达产物进行了鉴定和分析。综合分析两种表达结果发现，在融合型表达中ORF3蛋白与其融合标签蛋白(谷胱甘肽S一转移酶)之间存在免疫交叉反应，而且这种融合标签蛋白在空间结构上可能对ORF3蛋白中的抗体结合位点有掩盖作用。

Expression and identification of ORF3 ptrotein of Hepatitis E Virus in E. coli DE3

In this study the cloned segments of the open reading frame3(ORF3) of HEV were inserted into the pET42 expression plasmids to efficiently express the ORF3 protein in E coli(DE3) with two different strategies,which were drived by the T7 promotor, and the expressions were induced by addition of IPTG to the culture.The expressed proteins were analysed by 15% SDS PAGE, Western blot and competitive inhibition ELISA respectively. The ELISA results implied that the antibody binding site of ORF3 protein may be covered up by GST fusion mark protein and there is a cross reaction between the two proteins.