变形链球菌唾液结合区段(SBR)在大肠杆菌中的表达

Effective expression of SBR gene in E.Coli.JM109(DE3)

目的构建含变形链球菌唾液结合区段(SBR)基因的原核表达载体,并在大肠杆菌JM109(DE3)中诱导表达。方法采用定向克隆方法将变形链球菌唾液结合区段(SBR)基因插入表达载体pcMVT 7,构建重组原核表达质粒pcMVT 7-SBR,转化大肠杆菌JM109(DE3),IPTG诱导表达,亲和层析纯化SBR目的蛋白。结果经酶切鉴定及DNA序列测定,重组质粒pcMVT 7-SBR序列及阅读框架正确,亲和层析纯化得到SBR融合蛋白。结论成功构建了含变形链球菌唾液结合区段(SBR)基因的原核表达载体,为防龋疫苗的动物实验研究奠定基础。

Objective：To obtain the prokaryotic expression vector containing the saliva binding region （SBR） gene of Streptococcus mutans. Methods： By directional cloning method, SBR gene fragment was cloned into the expression vector pcMVT7 and the recombinant plasmid pcMVT7-SBR was transformed to E. coli. JM109 （ DE3）, then its expression with IPTG was induced, and finally target protein was purified by affinity chromatography. Results： Restriction endonuclease and DNA sequencing techniques were used to identify the recombinant plasmid DNA. The results were correspondent with the initial design. The C-terminal 6 x His tagged SBR fusion protein was induced expression in JM109（ DE3 ） and was puri- fied by affinity chromatography. The expression rate of target protein was 29.73%. Conclusion ： The prokaryotic expression vector containing the saliva binding region （SBR） gene of Streptococcus mutans is constructed successfully, which lays a good foundation for animal experiment of anti-caries vaccine.