title: MALDI analysis of Bacilli in spore mixtures by applying a quadrupole ion trap time-of-flight tandem mass spectrometer.
abstract: A novel ion trap time-of-flight hybrid mass spectrometer (qIT-TOF MS) has been applied for peptide sequencing in proteolytic digests generated from spore mixtures of Bacilli. The method of on-probe solubilization and in situ proteolytic digestion of small, acid-soluble spore proteins has been recently developed in our laboratory, and microorganism identification in less than 20 min was accomplished. In this study, tryptic peptides were generated in situ from complex spore mixtures of B. subtilis 168, B. globigii, B. thuringiensis subs. Kurstaki, and B. cereus T, respectively. MALDI analysis of bacterial peptides generated was performed with an average mass resolving power of 6200 and a mass accuracy of up to 10 ppm using a trap-TOF tandem configuration. Precursor ions of interest were usually selected and stored in the quadrupole ion trap with their complete isotope distribution by choosing a window of +/- 2 Da. Sequence-specific information on isolated protonated peptides was gained via tandem MS experiments with an average mass resolving power of 4450 for product ion analysis, and protein and bacterial sources were identified by database searching.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA. bwarscheid@hotmail.com
authors.forename: Bettina
authors.initials: B
authors.lastname: Warscheid
authors.forename: Kathryn
authors.initials: K
authors.lastname: Jackson
authors.forename: Chris
authors.initials: C
authors.lastname: Sutton
authors.forename: Catherine
authors.initials: C
authors.lastname: Fenselau
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000737:chemistry / Q000302:isolation & purification*; D001409:Bacillus cereus / Q000737:chemistry / Q000302:isolation & purification; D001412:Bacillus subtilis / Q000737:chemistry / Q000302:isolation & purification; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D030562:Databases, Protein; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013171:Spores, Bacterial / Q000737:chemistry / Q000302:isolation & purification*; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010446:Peptide Fragments; D014269:Trifluoroacetic Acid; D014357:Trypsin