钩端螺旋体血小板激活因子乙酰水解酶基因特征分析

Characteristic analysis of paf-ah gene from Leptospira interrogens

目的 由于钩端螺旋体病的主要特征之一是组织器官广泛性出血 ,出血部位发生在黏膜、脏器、浆膜和皮肤等处 ,严重者出现大面积肺弥散性出血、咳血 ,是危重钩端螺旋体病早期最常见的死因 ,其致病机理仍不清楚。本文使用生物信息学软件分析钩端螺旋体基因LA2 14 4 (血小板激活因子乙酰化酶 ,PafAH)所编码蛋白的结构和功能 ,并探讨其在致病过程中的作用。方法 使用NCBI ,Swissprot/TrEMBL ,ProDom ,Pfam ,Jpred2 ,SWISS -MODEL ,TMpred ,SignalP ,ClustW对问号钩端螺旋体黄疸出血型赖株全基因组ORF基因诠释 ,编码蛋白进行在线分析 ,并使用Bioedit软件进行氨基酸同源性比较分析。结果 确定了问号钩端螺旋体黄疸出血型赖株血小板激活因子乙酰化酶基因 ,该基因编码蛋白质与哺乳动物 pafAH在一级结构上相似性达 4 2 % ,以牛脑 pafAH(Ib)γ亚基 (1WAB/PDB)为模件模拟该蛋白三级结构 ,发现两者立体结构与非常相似 ,催化位点完全相同 ,均由Ser-His-Asp组成催化三合体。结论 该基因可能与钩体染色体所编码的胶原酶基因 ,溶菌酶基因 ,YopM基因 ,VwA基因协同在钩端螺旋体病出血过程中起作用 。

Aim The importance of pulmonary hemorrhage as a lethal complication of leptospirosis has become more widely recognized,but the pathogenetic mechamisms have not been clearly understood Our aim is to annotate pafah (platelet activating factor acetylhydrolase) genes,predict the protein structure and function ,then explore the relationship with hemorrhage and haemoptysis Methods Using on-line database NCBI,Swissprot/TrEMBL,Jpred 2,SWISS-MODEL,TMpred,SignalP,ClustW et al for annotation,and using local software Bioedit to analyse PafAH amino acid sequence similarities from L interrogans and mammal Results pafah gene of Leptospira interrogans,which share 42% similarities on the primary structure and identical catalysis site (Ser-His-Asp) by simulating bovine brain PAFAH(Ib)α2 subunit (1WAB/PDB) have been analysised Conclusion pafah gene combined with other genes such as vwa,cola,acm,YopM have been presumed to act cooperatively at hemorrhage and haemoptysis