title: Tandem mass spectrometry of intact proteins for characterization of biomarkers from Bacillus cereus T spores.
abstract: Intact protein biomarkers from Bacillus cereus T spores have been analyzed by high-resolution tandem Fourier transform ion cyclotron resonance mass spectrometry. Two techniques have been applied for excitation of the isolated multiply charged precursor ion species: sustained off-resonance irradiation/collisionally activated dissociation and electron capture dissociation. Fragmentation-derived sequence tags and BLAST sequence similarity proteome database searches allow unequivocal identification of the major biomarker protein with unprecedented specificity. Sequence-specific fragmentation patterns further confirm protein identification. Moreover, methodology combining accurate mass measurements of intact proteins with additional information contained in a proteome database permits tentative assignment of several other protein biomarkers isolated from the B. cereus T spores. We argue that approaches involving tandem MS of protein biomarkers, combined with bioinformatics, can drastically improve the specificity of individual microorganism identification, particularly in complex environments.
authors.affiliation: Department of Chemistry, University of Maryland, College Park 20742, USA. demirev@wam.umd.edu
authors.forename: P A
authors.initials: PA
authors.lastname: Demirev
authors.forename: J
authors.initials: J
authors.lastname: Ramirez
authors.forename: C
authors.initials: C
authors.lastname: Fenselau
mesh_terms: D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000737:chemistry*; D015415:Biomarkers; D030562:Databases, Protein; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D013171:Spores, Bacterial / Q000737:chemistry
chemical_list: D015415:Biomarkers