变形链球菌表面蛋白编码基因载体质粒pMD-pac构建

Construction of recombinant plasmid carrying pac genes of Streptococcus mutans surface protein

目的:获取变形链球菌国内临床株表面蛋白PAC编码基因pac并构建载体质粒,为构建植物表达基因载体做前期准备。方法:以国内检出率最高的变形链球菌临床分离株(血清c型)的基因组DNA为模板,通过PCR扩增获取表面蛋白PAc编码基因pac;通过T-A克隆构建中间载体pMD18-pac质粒,对其分析鉴定。结果:目的基因成功的连接到中间载体上。结论:获取的目的基因经测序和比对表明,其与变形链球菌表面蛋白的相关编码基因在核苷酸序列和蛋白同源性上都很高,可以作为抗原基因进一步研究。

Objective：To obtain the pac gene encoding surface protein PAC of Streptococcus mutans（S, mutans）, which was isolated from clinical strain in China, and to construct the recombinant plasmids vector containing the pac gene,which will provide further study for edible plants vaccine against dental caries. Methods： According to the sequence of pac gene, a pair of pac gene specific primers was designed and synthesized;By using PCR the target DNA fragment was amplified from genome of serotype c of S. mutans which was highest frequency of clininal isolates in China. The recombinant intermediate vector pMD18-pac was constructed through T-A Cloning and identified by sequencing. Results： The sequences of cloned pac gene was high homology with that of pac gene reported from references. Conclusions：The sequence of pac gene obtained in this study can be used to further study for preparation of DNA vaccine against dentalcaries.