Ph-SA对金黄色葡萄球菌agr系统活性影响的初步研究

发布时间：2018-02-03 10:19

本文关键词： 抗菌多肽金黄色葡萄球菌密度阈值感应耐药性　出处：《四川大学》2005年硕士论文　论文类型：学位论文

【摘要】：金黄色葡萄球菌是引起院内感染和社区感染的重要致病菌之一,耐甲氧西林金黄色葡萄球菌(methicillin-resistent S.aureus,MRSA)的出现和近年来耐万古霉素的金黄色葡萄球菌的出现(Vancomycin-resistent S.aureus,VRSA)正严重威胁着人类健康,因此迫切地需要发展新型的抗菌素。 Ph-SA(Pheromonicin-SA Ph-SA)是本实验室以大肠菌素Ia(colicin Ia)和金黄色葡萄球菌的信息素AgrD1通过分子生物学方法构建的多结构域融合抗菌多肽。AgrD1可以将原本不能识别金黄色葡萄球菌的大肠菌素Ia引导至金黄色葡萄球菌胞膜的亲疏水作用区内,大肠菌素Ia的通道形成结构域就可以循亲疏水作用插入细菌胞膜,形成电压依赖性的离子通道,将细菌杀死。 AgrD是金黄色葡萄球菌密度阈值感应系统(accessory gene regulator system,agr)的信号分子,当其浓度达到一定的阈值,便会与金黄色葡萄球菌胞膜上的受体结合,通过二元信号传导系统启动基因的表达,促进金黄色葡萄球菌大部分毒力因子的分泌,与金黄色葡萄球菌的致病性密切相关。Ph-SA是一个融合蛋白,其结构特点相当于将AgrD1序列的氨基端连接在大肠菌素Ia的羧基端,同天然的AgrD1相比,它对agr系
[Abstract]:Staphylococcus aureus is one of the most important pathogens causing nosocomial and community infections. Methicillin-resistant Staphylococcus aureus. MRSA) and vancomycin-resistent S. aureus in recent years. VRSA is a serious threat to human health, so it is urgent to develop new antibiotics. Ph-SA(Pheromonicin-SA Ph-SAA is a coliform Ia(colicin Ia in our laboratory. Fusion of antimicrobial polypeptide. AgrD1 with the pheromone AgrD1 of Staphylococcus aureus by molecular biological method can guide coliform Ia which could not recognize Staphylococcus aureus originally. To the hydrophilic zone of the membrane of Staphylococcus aureus. The channel formation domain of coliform I _ a can be inserted into the cell membrane of bacteria through hydrophilic action to form a voltage-dependent ion channel and kill the bacteria. AgrD is a signal molecule of Staphylococcus aureus density threshold sensing system (accessory gene regulator system agrass). When the concentration reaches a certain threshold, it will bind to the receptor on the membrane of Staphylococcus aureus, and promote the secretion of most virulence factors of Staphylococcus aureus through the binary signal transduction system. Ph-SA is a fusion protein closely related to the pathogenicity of Staphylococcus aureus. Its structural characteristics are similar to the amino terminal of AgrD1 sequence to the carboxyl terminal of coliform Ia. Compared with the natural AgrD1, it can be applied to the agr system.
【学位授予单位】：四川大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R378

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