Chao Chien-Chung, Chelius Dirk, Zhang Terry, Mutumanje Elissa, Ching Wei-Mei
Viral and Rickettsial Diseases Department Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA.
Biochim Biophys Acta. 2007 Mar;1774(3):373-81. doi: 10.1016/j.bbapap.2007.01.001. Epub 2007 Jan 17.
Rickettsia prowazekii, an obligate intracellular Gram-negative bacterium, is the etiologic agent of epidemic typhus. We analyzed the proteome of the virulent Breinl strain of R. prowazekii purified from infected egg yolk sacs. Total proteins from purified R. prowazekii Breinl strain were reduced by dithiothreitol, alkylated by iodoacetic acid and digested with trypsin followed by analysis with an integrated two-dimensional liquid chromatography and mass spectrometry system (2D-LC/MS/MS). A comparison was made using previously analyzed proteome of the Madrid E strain and current analysis of the Breinl strain. For Breinl 251 proteins were identified, representing 30% of the total protein-encoding genes, using a shotgun 2D-LC/MS/MS proteomic approach. This result is identical to that of Madrid E strain. Among the identified proteins, 33 from Breinl and 37 from Madrid E have an unknown function. A methyltransferase, RP028/RP027, whose gene is mutated in the avirulent Madrid E strain but not in the virulent Breinl strain, was only detectable in the Breinl strain, consistent with the genetic mutation in Madrid E. This result suggests the possible relationship between this gene product and the virulence of the strains.
普氏立克次体是一种专性细胞内革兰氏阴性菌，是流行性斑疹伤寒的病原体。我们分析了从感染的卵黄囊中纯化的普氏立克次体强毒株布雷恩尔株的蛋白质组。用二硫苏糖醇还原纯化的普氏立克次体布雷恩尔株的总蛋白，用碘乙酸烷基化，并用胰蛋白酶消化，然后用集成二维液相色谱和质谱系统（2D-LC/MS/MS）进行分析。将其与先前分析的马德里E株蛋白质组和当前对布雷恩尔株的分析进行比较。使用鸟枪法2D-LC/MS/MS蛋白质组学方法，在布雷恩尔株中鉴定出251种蛋白质，占总蛋白质编码基因的30%。这一结果与马德里E株相同。在鉴定出的蛋白质中，布雷恩尔株有33种、马德里E株有37种功能未知。一种甲基转移酶RP028/RP027，其基因在无毒的马德里E株中发生突变，但在强毒的布雷恩尔株中未发生突变，仅在布雷恩尔株中可检测到，这与马德里E株的基因突变一致。这一结果表明该基因产物与菌株毒力之间可能存在关联。
