Proteomic Studies of Bacillus anthracis Reveal In Vitro CO2-Modulation and Expression During Infection of Extracellular Proteases

摘要: A comparative proteomic study of secretomes virulent and avirulent Bacillus anthracis strains in various culturing conditions, including those encountered the host (high CO2/bicarbonate), enabled identification approximately 70 proteins representing collectively more than 99% secretome. In-vivo expression 50 was established by 2-dimension Western-analysis using anti B. immune sera. Many abundant harbor features characteristic virulence determinants exhibit different patterns expression. In minimal medium, manifest similar protein signatures metalloprotease NprA, (previously suggested to act context a starvation-induced mechanism), represents 90% total Under high CO2/bicarbonate, NprA is repressed (possibly mechanism which preserves toxin integrity), while other proteins, bacterial toxins, are induced. One immunogens observed be induced under CO2-tension, HtrA. We investigated phenotype associated with disruption HtrA biochemical approaches. The HtrA- bacteria severely affected their ability respond stress fail secrete most extracellular protease NprA. Most surprisingly, cells do not possess S-layer. This unique may have important implications for role manifestation virulence. Furthermore, data show that distinct CO2/bicarbonate responsive chromosome-and plasmid-encoded regulatory factors modulate secretion potential novel factors, proteolytic activities.