Membranal polypeptides of Bacillus anthracis identified.

2004 JUN 2 - (NewsRx.com & NewsRx.net) -- Scientists have identified chromosomally encoded membranal polypeptides of Bacillus anthracis through a proteomic analysis.

"Bacillus anthracis is the causative agent of anthrax disease. Improvement of existing anthrax vaccines, which are currently based on the administration of Protective Antigen (the highly immunogenic nontoxic subunit of the bacterial toxin) may entail other bacterial immunogenic elements, part of which are predicted to reside on the surface of bacterial cells. In the present study, membranal proteins extracted from a stationary-phase culture of a nonvirulent B. anthracis strain, devoid of the native virulence plasmids pXO1 and pXO2, were separated by two-dimensional electrophoresis (2-DE) and a characteristic protein map was defined," scientists in Israel report.

"The proteomic analysis allowed matrix-assisted laser desorption/ionization-time of flight mass spectrometry-assisted identification of 86 protein spots which represent the product of 30 individual open reading frames (ORF)," said Theodor Chitlaru and colleagues at the Israel Institute for Biological Research. "Among these, a prevalent class of proteins was the S-layer proteins (which were found to represent more than 75% of the B. anthracis membranal fraction) and proteins containing S-layer homology (SLH)-membranal localization domains."

"Five novel SLH proteins, previously inferred only from bioinformatic ORF analysis (draft genome sequence), were identified and one was shown to be a highly abundant membranal protein," reported the researchers. "Western blots of the 2-DE gels ...