Division of Life Science, Korea Basic Science Institute, Daejeon 305-806, South Korea.
Diagn Microbiol Infect Dis. 2012 Apr;72(4):318-27. doi: 10.1016/j.diagmicrobio.2011.12.013. Epub 2012 Feb 4.
Streptococcus pneumoniae is an important human pathogen that causes a variety of diseases in both adults and children, such as pneumonia, bacteremia, meningitis, otitis media, and sinusitis. Despite their clinical importance, to date, there have been few proteomic studies of these strains for screening of virulence factors or diagnostic markers. In the present study, secreted proteins (secretome) of Streptococcus pneumoniae strains were enriched using ammonium sulfate precipitation and identified by the shotgun proteomic method using 1-dimensional electrophoresis liquid chromatography-mass spectrometry/mass spectrometry analysis. Characterization of the identified proteins revealed that 17.8% (42) of the secreted proteins possessed signal peptides. Twenty-one secreted proteins belonged to the extracellular group, and 4 secreted proteins belonged to the cell wall group. Well-known virulence factors (PrtA, PspC, PsaA, PbpA, PhtD, AmiA, ZmpB, Eno, and Ply) were included in the secreted protein fraction. Western blotting using antiserum against secreted protein mixtures showed that Gsp-781, Sphtra, NagA, PhtD, ZmpB, and Eno were strongly immunogenic. Our data suggest that the immuno-proteomic approach is a useful method for high-throughput identification of secreted proteins and screening of candidate vaccine antigens or diagnostic markers. Gsp-781 is introduced as a novel secreted antigen of Streptococcus pneumoniae.
肺炎链球菌是一种重要的人类病原体，可导致成人和儿童罹患多种疾病，如肺炎、菌血症、脑膜炎、中耳炎和鼻窦炎。尽管这些菌株具有重要的临床意义，但迄今为止，针对这些菌株进行的毒力因子或诊断标志物筛选的蛋白质组学研究很少。在本研究中，使用硫酸铵沉淀法富集肺炎链球菌株的分泌蛋白（分泌组），并通过 1 维电泳-液相色谱-质谱/质谱分析的 shotgun 蛋白质组学方法进行鉴定。鉴定出的蛋白质的特征分析表明，42 个（17.8%）分泌蛋白具有信号肽。21 个分泌蛋白属于细胞外组，4 个分泌蛋白属于细胞壁组。包含已知的毒力因子（PrtA、PspC、PsaA、PbpA、PhtD、AmiA、ZmpB、Eno 和 Ply）的分泌蛋白。使用针对分泌蛋白混合物的抗血清进行 Western blot 分析表明，Gsp-781、Sphtra、NagA、PhtD、ZmpB 和 Eno 具有很强的免疫原性。我们的数据表明，免疫蛋白质组学方法是一种用于高通量鉴定分泌蛋白和筛选候选疫苗抗原或诊断标志物的有用方法。Gsp-781 被引入为肺炎链球菌的一种新型分泌抗原。
