For study the protection of truncate subtilisin-like serine protease(sspA) against Streptococcus suis type 2 in mice,the truncate sspA encoding aa 91-aa 323 sequence was cloned and expressed in E.coli.The recombinant protein was about 45.6 ku and recognized by positive serum.In addition,mice was immunized with the purified protein and challenged with the fatal dose of S.suis 2.The results showed that the recombinant protein only provided 15% protection in mice against the challenge with S.suis 2.
猪链球菌病是重要的人兽共患病,枯草杆菌素样蛋白酶(sspA)可能是2型猪链球菌(Streptococcussuis type 2,SS2)关键的毒力因子和保护性抗原。SS2编码sspA的基因与嗜热链球菌prtS基因具有95.9%相似性,并含有典型的枯草杆菌蛋白酶家族的三联催化结构域:A sp200-H is239-Ser568,其C?