Lehrstuhl für Analytische Chemie, Biomolekulare Massenspektrometrie, Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum, Bochum, Germany.
Proteomics. 2012 Aug;12(14):2319-30. doi: 10.1002/pmic.201100636.
Since multiresistant bacterial strains are more widespread and the victim numbers steadily increase, it is very important to possess a broad bandwidth of antimicrobial substances. Antibiotics often feature membrane-associated effect mechanisms. So, we present a membrane proteomic approach to shed light on the cellular response of Escherichia coli as model organism to the hexapeptide MP196, which is arginine and tryptophan rich. Analyzing integral membrane proteins are still challenging, although various detection strategies have been developed in the past. In particular, membrane proteomics in bacteria have been conducted very little due to the special physical properties of these membrane proteins. To obtain more information on the cellular response of the new compound group of small peptides, the tryptophan- and arginine-rich hexapeptide MP196 was subject to a comprehensive quantitative membrane proteomic study on E. coli by means of metabolic labeling in combination with membrane lipid analyses. This study provides in total 767 protein identifications including 185 integral membrane proteins, from which 624 could be quantified. Among these proteins, 134 were differentially expressed. Thereby, functional groups such as amino acid and membrane biosynthesis were affected, stress response could be observed, and the lipid composition of the membrane was significantly altered. Especially, the strong upregulation of the envelope stress induced protein. Spy indicates membrane damage, as well as the downregulation of the mechano-sensitive channel MscL beside others. Finally, the exceptional downregulation of transport systems strengthens these findings.
由于多耐药菌株更为广泛，且受害者人数不断增加，因此拥有广泛的抗菌物质带宽非常重要。抗生素通常具有膜相关的作用机制。因此，我们提出了一种膜蛋白质组学方法，以阐明大肠杆菌作为模型生物对富含精氨酸和色氨酸的六肽 MP196 的细胞反应。尽管过去已经开发了各种检测策略，但分析整合膜蛋白仍然具有挑战性。特别是由于这些膜蛋白的特殊物理性质，细菌中的膜蛋白质组学研究很少进行。为了获得有关新型小肽化合物组的细胞反应的更多信息，对富含色氨酸和精氨酸的六肽 MP196 进行了综合定量膜蛋白质组学研究，通过代谢标记与膜脂质分析相结合，对大肠杆菌进行了研究。这项研究总共提供了 767 种蛋白质鉴定，包括 185 种整合膜蛋白，其中 624 种可以定量。在这些蛋白质中，有 134 种表达差异。因此，影响了氨基酸和膜生物合成等功能组，观察到应激反应，并显著改变了膜的脂质组成。特别是，强烈上调了 envelope stress induced protein。Spy 表明存在膜损伤，同时下调了其他 mechano-sensitive channel MscL。最后，运输系统的异常下调加强了这些发现。
