便于产物纯化的融合表达载体的构建

本文构建了便于目的产物纯化的融合表达载体pBG-2，即在pBV220质粒的P_RP_L启动子下游插人链球菌荡白G的IgG F_c结合区基因片段（编码60个氨基酸），该插人片段下游仍保留多克隆位点并引人剪切融合蛋白的特异位点．SDS-PAGE显示，在大肠杆菌中融合基因片段能表达到占菌体总蛋白的30%的水平，Western-blot结果表明，表达产物能很好地与IgG结合．

The Construction of A Fusion Vector Which Facilitates Protein Purification

A fusion cxprcssion vector plasmid pBG-2 was constructed by inserting the IgG Fc bindingdomain (FBD, 60AA) of protcin G downstream to the PRPL promoter in plasmid pBV220. There aremultiple cloning sites downstream to the FBD gene fragment, this facilitiates thc target gene fusion expression. Two spccific sitcs for chemical clcavage of protcins wcle introduccd, this makcs the purificd target protein to recovcr its native coformation SDS-PAGE showcd that the FBD was expressed up to30% of the total solub1e ccll proteins in E. coli RR l, and Western-blot displayed that the FBD had affinity toIgG.