弗氏志贺菌2a GadB蛋白的功能研究

GadB of Shigella flexneri 2a:a pilot study

目的探究gadB基因的潜在功能及其对弗氏志贺菌2a 301株致病能力的影响。方法利用λ-Red重组系统构建弗氏志贺菌2a 301株的gadB缺失突变株,随后进行基本的表型实验测评,并初步评价其毒力,最后制备突变株和野生株全菌蛋白样品,利用双向电泳技术比较二者在蛋白表达谱上的差异。结果成功获得gadB基因缺失株;生化实验发现缺失株不能利用甘油发酵;而豚鼠角膜实验发现突变株炎症反应稍轻于野生株;全菌蛋白表达谱中发现10个差异蛋白。结论利用双向电泳鉴定到一些可能与GadB有关的蛋白,为gadB潜在功能的研究提供了线索。

Objective To investigate the potential functions of gadB in Shigella flexneri 2a.Methods Gene gadB was knocked out from S.flexneri 2a stain 301 by λ-Red recombinant system.The biochemical phenotypes and the virulence of the mutant strain was tested.Then,two-dimensional gel electrophoresis（2-DE） was used to identify the differentially expressed proteins between the wild-type strain and the mutant strain.Results The null-mutant strain of gadB was successfully constructed that could not use glycerol as the only carbon source.Sereny test revealed that the virulence of gadB mutant was slightly weaker than that of the wild-type strain.A total of 10 proteins were identified as differentially expressed proteins according to the comparative proteomic results.Conclusion Deletion of gadB can influence the expression of some proteins.These data provide some clues to the function research of gadB.