大片吸虫组织蛋白酶L1在大肠杆菌中的表达及纯化

Expression and purification of the recombinant Fasciola gigantica cathepsin L1 in Escherichla coli

利用PCR方法从pET28/FgCL1重组质粒中扩增FgCL1基因,定向克隆至原核表达载体pGEX-4T-2中,构建重组质粒pGEX/FgCL1,将该重组质粒转化大肠杆菌BL21中,转化子经IPTG诱导表达。重组蛋白以包涵体形式存在,相对分子质量为61 000。Western-blot、ELISA试验结果显示,纯化后的重组蛋白能被自然感染大片吸虫的牛血清所识别,表达产物具有良好的抗原性。

The FgCL1 coding region was amplified from recombinant PET28/FgCL1. The PCR products were then cloned into pMD18-T vector, and the recombinant was screened by PCR, enzyme digestion and sequencing. Then it was subcloned to the expression vector pGEX-4T-2. The recombinant plasmid was transformed into E. coli BL21 （DE3） with IPTG induction,and the recombinant product was analyzed by Western-blot and ELISA. It was demonstrated that the FgCL1 gene was successfully cloned and subcloned into vectors. With the positive clones induced by IPTG,the molecular weight of the whole expression protein was 61 000 on SDS-PAGE. A fusion protein recognized by sera of bovine naturaly infected with F. gigantica has been obtained.