用融合蛋白在大肠杆菌中高表达百日咳杆菌毒素蛋白S＿3亚基基因

HIGH LEVEL EXPEESSION Bordetella Pertussis TOXIN s3 SUBUNT BY THE FUSING PROTEIN TECHNIQUE IN Escherichia coli

用多聚酶链反应（ＰＣＲ）和基因重组技术通过百日咳毒素Ｓ＿３亚基基因和高表达质粒ｐＭＡＬ－Ｃ构建了麦芽糖结合蛋白（ＭＢＰ）和（Ｓ＿３）亚基蛋白的融合基因，并在大肠杆菌中高效表达了（ＭＢＰ－Ｓ＿３）融合蛋白。该融合蛋白产率占细胞总蛋白含量的２５％，并且能用蛋白酶因子Ｘａ将融会蛋白切开，得到ＭＢＰ（４２ＫＤ）和Ｓ＿３亚基蛋白（２１．８７ＫＤ）．该方法表达式效率高。纯化过程简单，为基因工程技术生产该毒素提供了新的途径。

sing Polyinerase Chain Reaction(PCR)and recombinant DNA techniques,a fusing genevector inc luding maltose binding protein(MBP)and pertussis toxin S3(PTX-S3) subunit proteinis constructed by PTX-S3 gene and a high level expressioa plasmid pMAL-C. High levelexpressi on of the fusing protein may be produced by the fusing pla smid in E. coli,the fusingprotein (MW,63.87KD)yield is about 25% in the whole cell protein. MBP(MW,42KD) andPTX-S3(MW,21.87KD)may be obtained by cutting the fusing protein with the factor-Xa. Themethod have a high level expression and simple purification pmcess,which will be a verv usefulroad to eontribute and produce PTX-S3 in E. coli.