Ruiz Lorena, Couté Yohann, Sánchez Borja, de Los Reyes-Gavilán Clara G, Sanchez Jean-Charles, Margolles Abelardo
Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (CSIC), Ctra Infiesto s/n, 33300, Villaviciosa, Asturias, Spain.
Biomedical Proteomics Research Group, Department of Structural Biology and Bioinformatics, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 14, Switzerland.
Microbiology (Reading). 2009 Mar;155(Pt 3):957-967. doi: 10.1099/mic.0.024273-0.
Host-bacteria interactions are often mediated via surface-associated proteins. The identification of these proteins is an important goal of bacterial proteomics. To address how bile can influence the cell-envelope proteome of Bifidobacterium longum biotype longum NCIMB 8809, we analysed its membrane protein fraction using stable isotope labelling of amino acids in cell culture (SILAC). We were able to identify 141 proteins in the membrane fraction, including a large percentage of the theoretical transporters of this species. Moreover, the envelope-associated soluble fraction was analysed using different subfractionation techniques and differential in-gel fluorescence electrophoresis (DIGE). This approach identified 128 different proteins. Some of them were well-known cell wall proteins, but others were highly conserved cytoplasmic proteins probably displaying a 'moonlighting' function. We were able to identify 11 proteins in the membrane fraction and 6 proteins in the envelope-associated soluble fraction whose concentration varied in the presence of bile. Bile promoted changes in the levels of proteins with important biological functions, such as some ribosomal proteins and enolase. Also, oligopeptide-binding proteins were accumulated on the cell surface, which was reflected in a different tripeptide transport rate in the cells grown with bile. The data reported here will provide the first cell-envelope proteome map for B. longum, and may contribute to understanding the bile tolerance of these bacteria.
宿主与细菌的相互作用通常是通过表面相关蛋白介导的。鉴定这些蛋白是细菌蛋白质组学的一个重要目标。为了研究胆汁如何影响长双歧杆菌长亚种NCIMB 8809的细胞包膜蛋白质组，我们使用细胞培养中氨基酸的稳定同位素标记（SILAC）分析了其膜蛋白组分。我们能够在膜组分中鉴定出141种蛋白，其中包括该物种大部分理论转运蛋白。此外，使用不同的亚分级技术和差异凝胶荧光电泳（DIGE）分析了包膜相关的可溶性组分。这种方法鉴定出128种不同的蛋白。其中一些是众所周知的细胞壁蛋白，但其他一些是高度保守的细胞质蛋白，可能具有“兼职”功能。我们能够鉴定出膜组分中的11种蛋白和包膜相关可溶性组分中的6种蛋白，它们在胆汁存在下浓度发生变化。胆汁促进了具有重要生物学功能的蛋白水平的变化，如一些核糖体蛋白和烯醇化酶。此外，寡肽结合蛋白在细胞表面积累，这反映在用胆汁培养的细胞中不同的三肽转运速率。本文报道的数据将提供首张长双歧杆菌细胞包膜蛋白质组图谱，并可能有助于理解这些细菌的胆汁耐受性。
