副溶血性弧菌群体感应蛋白CqsA的原核表达

Prokaryotic Expression of the Quorum-sensing Protein CqsA from Vibrio parahaemolyticus

副溶血性弧菌CqsA是一种推测的信号分子合成酶,其合成的信号分子在群体感应系统中可能具有重要的调控作用。从副溶血性弧菌ATCC17802中克隆cqsA基因,构建重组质粒pET22b-cqsA。测序后转化大肠杆菌BL21进行IPTG诱导表达,使用SDS-PAGE分析融合蛋白的表达状况,并通过6×His-Tag进行Western blotting检测。结果显示,经0.6 mmol/L IPTG诱导4h,目的基因以包涵体形式高效表达,表达的融合蛋白大小约为49 kD,与理论值相符(437 aa)。表明副溶血性弧菌群体感应蛋白CqsA在大肠杆菌中成功表达,为后续寻找副溶血性弧菌群体感应信号分子,进一步探索副溶血性弧菌群体感应系统提供参考。

CqsA,a quorum-sensing-related protein in Vibrio parahaemolyticus,is a putative autoinducer synthase,and the autoinducer synthesized by CqsA maybe is a major regulator in quorum sensing system.cqsA gene was cloned from V.parahaemolyticus ATCC17802 and inserted into the expression vector pET-22b.After sequencing the recombinant vector pET22b-cqsA was transformed into Escherichia coli BL21 and induced by IPTG,and then the fusion protein was analyzed by SDS-PAGE and verified by Western blotting employed 6×His-Tag.The results showed that the pET22b-cqsA could be able to express efficiently in a form of inclusion body under the induction of 0.6 mmol/L IPTG for 4 h.The molecular weight of the fusion protein was 49 kD,and this result matched the theory value（437 aa）.In this experiment,V.parahaemolyticus quorum-sensing protein CqsA was expressed correctly in E.coli BL21.