链球菌烯醇化酶与致热外毒素B成熟的相关性  

Correlation of Enolase and the Maturation of SpeB in Streptococcus pyogenes

作　　者：胡珊[1] 马超[1] 李学如[1] 黎明[1] 刘彦宏[1] 江南屏[1] 郭泰林[1] 姚宁[1] 

机构地区：[1]西南交通大学生命科学与工程学院,成都610031

出　　处：《高等学校化学学报》2013年第4期886-892,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:31070117;31171203);中央高校基本科研业务专项资金(批准号:SWJTU11ZT25);国家大学生创新性实验计划(批准号:111061351)资助

摘　　要：在化脓性链球菌致热外毒素B(SpeB)活性阳性菌株对数生长末期的细胞培养液中发现1个分子量约为50000的蛋白,该蛋白随后消失;用聚丙烯酰胺凝胶电泳(SDS-PAGE)分离,串联质谱(MS/MS)分析确认该蛋白为链球菌烯醇化酶(Enolase,Eno);通过基因敲除方法构建eno基因缺失突变株,研究了Eno蛋白对SpeB活性形成的影响.结果表明,eno基因的缺失推迟SpeB成熟的时间;通过Far-Western blot分析显示,Eno与SpeB之间能发生相互作用.考虑到化脓性链球菌胞外蛋白通过同一通道分泌,推测Eno可能参与了SpeB酶原分泌到胞外的过程,为新发现的SpeB蛋白分子伴侣.Group A Streptococci（GAS） is an important Gram-positive human pathogen, which causes mild to severe diseases. The ability of GAS to cause infection is associated with the production of an array of secreted and cell-wall associated virulence factors. One key secreted virulence factor is a cysteine protease called strep- tococcal pyrogenic exotoxin B （SpeB）. This protein is initially secreted as a 40000 precursor zymogen, and is subsequently cleaved to a 28000 mature form. The conversion of the zymogen form of SpeB is extremely com- plex and unclear. In this paper we reported a protein involved in the maturation of SpeB in the supernatant of Group A Streptococci. This protein was the streptococcus host plasminogen receptor, enolase （Eno） identified by MS/MS analysis. We constructed the eno in-deletion mutants by the method of gene knock out and investi- gated the correlation of enolase and maturation of SpeB in GAS. Western blot analysis and protease assays re- vealed a delay in the maturation of SpeB in supernatant of the eno in-deletion mutants comparing with the wild type strains. Far-Western blot analysis showed that SpeB can bind to Eno, which interact with each other. These data imply that the function of Eno, as like HtrA and RopA, is a chaperone, the regulation of protease activity and the mechanism of secretion in GAS.

关 键 词：烯醇化酶 链球菌致热外毒素B eno基因缺失突变株 化脓性链球菌 

分 类 号：O629.7[理学—有机化学] Q936[理学—化学]