河南华溪蟹金属硫蛋白的GST融合表达及工程菌吸附重金属的研究

Expression of Sinopotamon henanense Metallothionein in Escherichia coli Enhance Heavy Metals Biosorption

目的:构建河南华溪蟹金属硫蛋白(MT)的GST融合表达系统,诱导其可溶性表达,并检测转MT工程菌吸附重金属的能力。方法:采用基因工程技术,将河南华溪蟹MT的cDNA克隆至原核表达载体pGEX-6p-1,转化大肠杆菌BL21(DE3),SDS-PAGE鉴定融合蛋白的表达。在此基础上采用火焰原子吸收分光光度计测定工程菌对重金属离子Cu^(2+)、Cd^(2+)、Zn^(2+)的吸附能力。结果:pGEX-6p-1-MT重组质粒构建成功,SDS-PAGE分析表明GST-MT为可溶性表达,表达菌体对3种重金属的生物吸附能力均显著高于空菌体(P<0.01)。结论:实现了华溪蟹MT的GST融合表达,转MT工程菌对Cu^(2+)、Cd^(2+)、Zn^(2+)具有显著吸附作用,且对Cd^(2+)的吸附作用最强。

Objective： To express soluble Sinopotamon henanense metallothionein（MT） fused with GST in Escherichia coil and detect heavy metals biosorptions of engineered bacteria. Methods： MT cDNA from S.henanense was inserted into the prokaryotic expression vector pGEX-6p-1 and the recombinant plasmid pGEX-6p-1-MT was constructed. Then the recombinant plasmid was transformed into E.coli BL21（DE3） and the fusion protein GST-MT was expressed by IPTG induction. Subsequently, the biosorptions of Cu^2＋, Cd^2＋ and Zn^2＋ by the engineered bacteria were determined by flame atomic absorption spectrophotometer. Results： pGEX-6p-1-MT recombinant plasmid was constructed successfully, and engineered bacteria absorbed three heavy metals significantly higher than control bacteria（P〈0.01）. Conclusion： The recombinant protein GST-MT was obtained and the engineered bacteria had signifi- cant Cu^2＋, Cd^2＋ and Zn^2＋ biosorption effects compared with control bacteria.