炭疽芽孢杆菌S-层蛋白功能研究进展

S-layer proteins of Bacillus anthracis:research progress

炭疽芽孢杆菌是人畜共患病炭疽的病原菌。目前,对炭疽杆菌2个毒力大质粒(编码主要毒力基因的pXO1与编码合成荚膜基因的pXO2)的研究比较深入;炭疽杆菌细胞壁与荚膜间还存在一种蛋白性质的类晶体(paracrystalline)结构:S-层(surface-layer,表层)结构。炭疽杆菌的S-层蛋白主要为表面排列蛋白(surface array pro-tein,Sap)和胞外抗原1(extracellular antigen 1,EA1),此外,在炭疽杆菌中还存在其他一些与S-层相关的蛋白,了解这些蛋白的相互作用及免疫机制对深入认识炭疽杆菌的致病机制具有重要意义。本文将就近年来关于炭疽杆菌S-层蛋白成分、与细胞壁的连接、S-层基因的调控、致病性及其与宿主免疫机制的关系等方面的研究进展做一简要综述。

Bacillus anthracis is the etiological agent of anthrax.Currently,plasmids pXO1 and pXO2 of B.anthracis,which were encoding the virulence genes and capsule synthesis genes respectively,have been studied thoroughly.However,the S-layer,a protein paracrystalline structure that exists between the capsule and the cell wall of B.anthracis,is less known.Sap（surface array protein） and EA1（extracellular antigen 1） are the major proteins of S-layer as well as some other relative proteins in B.anthracis.Investigation of the interaction of these proteins and their immunologic mechanism is vital for understanding the pathogenesis of B.anthracis.This brief review will focus on recent researches on the components of S-layer proteins,their linkage with the cell wall and the regulation patterns of their encoding genes of S-layer proteins,their role in the pathogenesis of B.anthracis,and the relationship between S-layer proteins and host immune systems.