Brucellosis is a zoonotic infection caused by bacteria of the genus Brucella. The species, B. abortus and B. melitensis, major causative agents of human brucellosis, share remarkably similar genomes, but they differ in their natural hosts, phenotype, antigenic, immunogenic, proteomic and metabolomic properties. In the present study, label-free quantitative proteomic analysis was applied to investigate protein expression level differences. Type strains and field strains were each cultured six times, cells were harvested at a midlogarithmic growth phase and proteins were extracted. Following trypsin digestion, the peptides were desalted, separated by reverse-phase nanoLC, ionized using electrospray ionization and transferred into an linear trap quadrapole (LTQ) Orbitrap Velos mass spectrometer to record full scan MS spectra (m/z 300–1700) and tandem mass spectrometry (MS/MS) spectra of the 20 most intense ions. Database matching with the reference proteomes resulted in the identification of 826 proteins. The Cluster of Gene Ontologies of the identified proteins revealed differences in bimolecular transport and protein synthesis mechanisms between these two strains. Among several other proteins, antifreeze proteins, Omp10, superoxide dismutase and 30S ribosomal protein S14 were predicted as potential virulence factors among the proteins differentially expressed. All mass spectrometry data are available via ProteomeXchange with identifier PXD006348.

中文翻译：

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布鲁氏菌，流产布鲁氏菌和布鲁氏菌布鲁氏菌的近亲种的泛蛋白质组学分析和蛋白质丰度的阐明。

布鲁氏菌病是由布鲁氏菌属细菌引起的人畜共患感染。该物种，流产双歧杆菌和melitensis人布鲁氏菌病的主要病原体具有非常相似的基因组，但它们的天然宿主，表型，抗原性，免疫原性，蛋白质组学和代谢组学性质不同。在本研究中，无标签定量蛋白质组学分析用于研究蛋白质表达水平的差异。将类型菌株和田间菌株分别培养六次，在对数生长期收获细胞并提取蛋白质。胰蛋白酶消化后，将肽脱盐，通过反相nanoLC分离，使用电喷雾电离将其电离，并转移到线性阱四极杆（LTQ）Orbitrap Velos质谱仪中，以记录全扫描MS光谱（m / z300-1700）和20种最强离子的串联质谱（MS / MS）光谱。与参考蛋白质组匹配的数据库可鉴定出826种蛋白质。鉴定出的蛋白质的基因本体簇揭示了这两种菌株在双分子转运和蛋白质合成机制上的差异。在其他几种蛋白质中，抗冻蛋白质，Omp10，超氧化物歧化酶和30S核糖体蛋白质S14被预测为差异表达的蛋白质中的潜在毒力因子。所有质谱数据都可以通过ProteomeXchange获得，其标识符为PXD006348。