通过同源性比较及生物信息学分析,发现猪链球菌2型srtBCD菌毛岛上菌毛辅助亚基编码基因SSU2099,PCR扩增目的片段,克隆入表达载体pET32a中原核表达,亲和层析法纯化重组蛋白。ELISA结果显示重组蛋白能够刺激小鼠产生高效价的免疫抗体,动物保护性实验表明该蛋白具有良好的免疫保护作用。提示菌毛亚基编码基因SSU2099是重要的疫苗候选分子,进一步研究该蛋白的定位和功能对于系统阐释srtBCD菌毛岛在猪链球菌2型致病机制中的作用有重要意义。
An open reading fragment,SSU2099,encoding pilus gene from srtBCD pilus island was identified based on bioinformatics analysis of the genome sequence of 05ZYH33 and alignment with relative protein family.The target DNA fragment was amplified using a pair of primers specific to SSU2099 gene.SSU2099 gene was cloned into prokaryotic expression plasmid pET32a subsequently,and the recombinant protein was expressed and purified.The mice anti-SSU2099 serum was obtained by immunizing mice with recombinant SSU2099 protein,and the titer of the serum was analyzed by ELISA.Animal test showed that vaccinating mice with recombinant SSU2099 confer a significant protection,which indicated that SSU2099 can serve as a novel vaccine candidate.Further studying of the localization and function of SSU2099 may adds novel insights into the role that srtBCD pilus island plays in pathogenicity of Streptococcus suis 2.