锰离子对肺炎链球菌影响的蛋白质组学研究

发布时间：2018-01-17 01:30

本文关键词：锰离子对肺炎链球菌影响的蛋白质组学研究　出处：《暨南大学》2011年硕士论文　论文类型：学位论文

【摘要】：对于很多致病性微生物而言,锰离子是其生存和感染的必须微量元素,然而宿主环境中的锰离子是非常微量的,仅从几个纳摩尔到几十微摩尔,因此,致病菌必须保证自己能从宿主环境中摄入足量的锰。肺炎链球茵是一种常见的致病性微生物,能在人群当中引发多种疾病,如肺炎、中耳炎、细菌性脑膜炎等。根据已有的报道,肺炎链球菌中存在着一个重要的ABC锰转运蛋白系统PsaABC。其中,PsaA是位于细胞膜外的金属结合受体,这个蛋白的缺失对细菌的毒力、生长等有较大的影响。目的：通过蛋白质组学的方法,了解锰离子缺失对肺炎链球菌的影响。方法：将肺炎链球菌分别培养在含锰与不含锰的限制性培养基中,分别收集全蛋白与膜蛋白,通过二维电泳寻找差异蛋白,并利用质谱技术对其进行鉴定。另外,将肺炎链球菌的野生型D39菌株和PsaA突变株分别培养于普通培养基中,用同样的方式对细菌的全蛋白进行比较。结果：肺炎链球菌在无锰条件下培养时,其全蛋白组分中有29个蛋白发生下调,3个发生上调；其膜蛋白组分中有15个蛋白发生下调,8个发生上调；细菌无锰培养时胞内的铁离子浓度是有锰培养时的2倍左右。PsaA突变株中,有50个蛋白发生下调,24个发生上调。结论：环境中锰离子的缺失,导致肺炎链球菌中很多蛋白的表达发生下调,这些蛋白包括各种与代谢有关的酶、一些糖类和肽类的转运蛋白,核糖体蛋白等。另外,培养环境中锰离子的缺乏将使得细菌从环境中摄取更多的铁离子以实现一定的代偿作用。PsaA是一个很重要的锰摄取蛋白,它的缺失不仅引起胞内锰离子的下降,还引起大量其他的蛋白表达的变化。
[Abstract]:For many pathogenic microorganisms, manganese ions are essential trace elements for their survival and infection. However, manganese ions in host environment are very small, ranging from a few nanomolor to dozens of micromoles, so. Pathogenic bacteria must ensure that they can absorb enough manganese from the host environment. Pneumonia streptomyte is a common pathogenic microorganism, which can cause many diseases in the population, such as pneumonia, otitis media. Bacterial meningitis and so on. According to existing reports, there is an important ABC manganese transporter system in Streptococcus pneumoniae, in which PsaA is a metal binding receptor located outside the cell membrane. The absence of this protein has a greater effect on the virulence and growth of bacteria. Objective: to investigate the effect of manganese deficiency on Streptococcus pneumoniae by proteomics. Methods: Streptococcus pneumoniae were cultured in the restricted medium containing manganese and no manganese respectively. The whole protein and membrane protein were collected respectively and the differential proteins were found by two-dimensional electrophoresis. In addition, the wild-type D39 strain and the PsaA mutant of Streptococcus pneumoniae were cultured in ordinary culture medium. The whole proteins of bacteria were compared in the same way. Results: when Streptococcus pneumoniae was cultured without manganese, 29 proteins were down-regulated and 3 upregulated. 15 of the membrane protein components were down-regulated and 8 were up-regulated. 50 proteins were down-regulated and 24 upregulated in the Mn-free culture of bacteria in which the concentration of Fe ~ (2 +) in the cells was about 2 times as high as that in the Mn-free culture. Conclusion: the loss of manganese ions in the environment leads to the down-regulation of many proteins in Streptococcus pneumoniae including various metabolism-related enzymes and some carbohydrate and peptide transporters. In addition, the lack of manganese ions in culture environment will make bacteria absorb more iron ions from the environment to achieve a certain compensatory effect. PsaA is a very important manganese uptake protein. Its deletion not only caused the decrease of intracellular manganese ion, but also caused the change of other protein expression.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R378

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