Benachour Abdellah, Morin Thierry, Hébert Laurent, Budin-Verneuil Aurélie, Le Jeune André, Auffray Yanick, Pichereau Vianney
USC INRA, IFR, Universite de Caen, France.
Can J Microbiol. 2009 Aug;55(8):967-74. doi: 10.1139/w09-052.
Secreted and surface proteins of bacteria are key molecules that interface the cell with the environment. Some of them, corresponding to virulence factors, have already been described for Enterococcus faecalis, the predominant species involved in enterococcal nosocomial infections. In a global proteomic approach, the identification of the most abundant secreted and surface-associated proteins of E. faecalis JH2-2 strain was carried out. These proteins were separated by gel electrophoresis or directly subjected to in vivo trypsinolysis and then analyzed by liquid chromatography - electrospray ion trap tandem mass spectrometry. Putative functions were assigned by homology to the translated genomic database of E. faecalis. A total of 44 proteins were identified, eight secreted proteins from the supernatant culture and 38 cell surface proteins from two-dimensional gel electrophoresis and in vivo trypsinolysis among which two are common to the two groups. Their sequences analysis revealed that 35 of the 44 proteins harbour characteristic features (signal peptide or transmembrane domains) consistent with an extracellular localization. This study may be considered as an important step to encourage proteomic-based investigations of E. faecalis cell surface associated proteins that could lead to the discovery of virulence factors and to the development of new therapeutic tools.
细菌的分泌蛋白和表面蛋白是连接细胞与环境的关键分子。其中一些与毒力因子相对应的蛋白，已经在粪肠球菌（肠球菌医院感染的主要病原菌）中有所描述。在一项全面的蛋白质组学研究中，对粪肠球菌JH2-2菌株中最丰富的分泌蛋白和表面相关蛋白进行了鉴定。这些蛋白质通过凝胶电泳分离，或直接进行体内胰蛋白酶消化，然后通过液相色谱-电喷雾离子阱串联质谱进行分析。通过与粪肠球菌翻译后的基因组数据库进行同源性比对来确定推定功能。共鉴定出44种蛋白质，其中8种是来自上清培养物的分泌蛋白，38种是通过二维凝胶电泳和体内胰蛋白酶消化鉴定出的细胞表面蛋白，其中有两种蛋白在两组中都存在。它们的序列分析表明，44种蛋白质中的35种具有与细胞外定位一致的特征（信号肽或跨膜结构域）。这项研究可被视为鼓励基于蛋白质组学研究粪肠球菌细胞表面相关蛋白的重要一步，这可能会导致发现毒力因子并开发新的治疗工具。
