title: Rapid characterization of Bacillus spores targeting species-unique peptides produced with an atmospheric pressure matrix-assisted laser desorption/ionization source.
abstract: New and improved strategies are eagerly sought for the rapid identification of microorganisms, particularly in mixtures. Mass spectrometry remains a powerful tool for this purpose. Small acid-soluble proteins (SASPs), which are relatively abundant in Bacillus spores, represent potential biomarkers for species characterization. Despite sharing extensive sequence homology, these proteins differ sufficiently in sequence for discrimination between species. This work focuses on the differences in sequence between SASPs from various Bacillus species. Compilation of SASP sequences from protein database searches, followed by in silico trypsin digestion and analysis of the resulting fragments, identified several species-specific peptides that could be targeted for analysis using mass spectrometry. This strategy was tested and found to be successful in the characterization of Bacillus spores both from individual species and in mixtures. Analysis was performed using an ion trap mass spectrometer with an atmospheric pressure MALDI source. This instrumentation offers the advantage of increased speed of analysis and accurate precursor ion selection for tandem mass spectrometric analysis compared with vacuum matrix-assisted laser desorption/ionization and time-of-flight instruments. The identification and targeting of species-specific peptides using this type of instrumentation offers a rapid, efficient strategy for the identification of Bacillus spores and can potentially be applied to different microorganisms.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA. patrickpribil@hotmail.com
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Pribil
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Patton
authors.forename: Gavin
authors.initials: G
authors.lastname: Black
authors.forename: Vladimir
authors.initials: V
authors.lastname: Doroshenko
authors.forename: Catherine
authors.initials: C
authors.lastname: Fenselau
mesh_terms: D000595:Amino Acid Sequence; D001274:Atmospheric Pressure; D001407:Bacillus / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D015415:Biomarkers; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis* / Q000737:chemistry*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013171:Spores, Bacterial / Q000737:chemistry*; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D015415:Biomarkers; D010455:Peptides