变异链球菌LuxS缺陷株甲基循环通路的恢复构建  

Complementation and function of methyl-metabolic pathway in Streptococcus mutans luxS null strain

作　　者：王玉霞[1] 高丽[1] 江文欣 马瑞[1] 唐子圣[1] 朱彩莲[1] 何智妍[1] 黄正蔚[1] 

机构地区：[1]上海交通大学医学院附属第九人民医院·口腔医学院牙体牙髓病科,上海市口腔医学重点实验室,上海200011

出　　处：《上海口腔医学》2014年第4期385-390,共6页Shanghai Journal of Stomatology

基　　金：国家自然科学基金(81070826;81371143;81300866);上海市启明星计划(12QH1401400)~~

摘　　要：目的:以变异链球菌LuxS缺陷株为模型,构建其密度感应缺陷的甲基循环恢复株。方法:以LuxS为阳性表达对照,通过在变异链球菌LuxS缺陷株中异源表达SahH,实现其代谢通路的恢复构建。通过Western印迹、反转录PCR和信号分子AI-2分泌检测,验证目的蛋白的表达。采用SAS8.0软件包对数据进行统计学分析。结果:Western印迹检测2种蛋白在大肠杆菌中均得到正确表达,验证了克隆载体的正常表达能力;反转录PCR验证了变异链球菌LuxS缺陷株中luxS及sahH mRNA的存在;发光实验证实LuxS阳性表达对照株AI-2的分泌能力恢复。结论:成功构建变异链球菌LuxS缺陷的代谢恢复株,为探讨LuxS的调控机制提供了分子生物学工具及实验对照。PURPOSE： To complement the activated methyl cycle（AMC） pathway at an AI-2 defect background in Streptococcus mutans（S. mutans） luxS null strain. METHODS： A sahH gene was amplified from Pseudomonas aeruginosa and introduced into the S. mutans luxS null strain to complement the methyl-metabolic disruption at an AI-2 defect background. Western blot, reverse-transcription PCR and AI-2 bioassay were performed to confirm the heterogenous expression of SahH in S. mutans luxS null strain. The data was statistically analyzed by SAS8.0 software package.RESULTS： LuxS and SahH were detected to express in Escherichia coli BL21 as well as their mRNA were confirmed to be successfully transcribed in S. mutans luxS null strain. AI-2 production was found in wide type S. mutans and its luxSintroduced luxS null strain but not found in the luxS null strain and its sahH and empty plasmid-introduced strains.CONCLUSIONS： A new S. mutans derivative with the AMC pathway complements while the AI-2 defect is constructed.

关 键 词：变异链球菌 生物膜 密度感应 LUXS SahH 

分 类 号：R378[医药卫生—病原生物学]