Identification of outer membrane proteins of Mycobacterium tuberculosis
Identification of outer membrane proteins of Mycobacterium tuberculosis
复制标题
DOI：
10.1016/j.tube.2008.02.004
复制
发表时间：
2008-11-01
期刊：
影响因子：
3.2
通讯作者：
Niederweis, Michael
中科院分区：
文献类型：
--
作者：
Song, Houhui;Sandie, Reatha;Niederweis, Michael
分枝杆菌的细胞壁包括一种不寻常的、渗透性极低的外膜。白色大肠杆菌使用60多种蛋白质来功能化其外膜，目前已知的只有两种分枝杆菌外膜蛋白（OMP）。耻垢分枝杆菌的孔蛋白MspA提供了原理证明，即完整的分枝杆菌OMP与革兰氏阴性菌的OMP共享β桶结构、不存在疏水性α螺旋并且存在信号肽。利用这些特性，在多步生物信息学方法来预测外膜蛋白的M。结核对M.结核病预计将输出。计算β链含量和β链两亲性的评分。革兰氏阴性菌的参考外膜蛋白定义了这些参数的阈值，M的144种未知功能的蛋白质满足这些阈值。结核通过一种新的两步实验方法验证了其中两个是OMP。Rv1698和Rv1973仅在M.在Western印迹实验中显示了牛BCG，而全细胞的蛋白酶K消化显示了这些蛋白质的表面可及性。这些发现证实了Rv1698和Rv1973确实定位于外膜，并使M的已知外膜蛋白的数量增加了两倍。结核值得注意的是，这些结果为生物信息学方法预测分枝杆菌外膜蛋白的有效性提供了证据，并表明M。结核病可能具有许多具有β桶结构的OMP。我们的研究结果为鉴定使M外膜功能化的蛋白质组铺平了道路。结核(C)2008爱思唯尔有限公司保留所有权利。
The cell wall of mycobacteria includes an unusual outer membrane of extremely low permeability. White Escherichia coli uses more than 60 proteins to functionalize its outer membrane, only two mycobacterial outer membrane proteins (OMPs) are known. The porin MspA of Mycobacterium smegmatis provided the proof of principle that integral mycobacterial OMPs share the beta-barrel structure, the absence of hydrophobic alpha-helices and the presence of a signal peptide with OMPs of gram-negative bacteria. These properties were exploited in a multi-step bioinformatic approach to predict OMPs of M. tuberculosis. A secondary structure analysis was performed for 587 proteins of M. tuberculosis predicted to be exported. Scores were calculated for the beta-strand content and the amphiphilicity of the beta-strands. Reference OMPs of gram-negative bacteria defined threshold values for these parameters that were met by 144 proteins of unknown function of M. tuberculosis. Two of them were verified as OMPs by a novel two-step experimental approach. Rv1698 and Rv1973 were detected only in the total membrane fraction of M. bovis BCG in Western blot experiments, while proteinase K digestion of whole cells showed the surface accessibility of these proteins. These findings established that Rv1698 and Rv1973 are indeed localized in the outer membrane and tripled the number of known OMPs of M. tuberculosis. Significantly, these results provide evidence for the usefulness of the bioinformatic approach to predict mycobacterial OMPs and indicate that M. tuberculosis likely has many OMPs with beta-barrel structure. Our findings pave the way to identify the set of proteins which functionalize the outer membrane of M. tuberculosis. (C) 2008 Elsevier Ltd. All rights reserved.