Characterization of Bacillus spore species and their mixtures using postsource decay with a curved-field reflectron.
A strategy is proposed for the rapid identification of Bacillus spores, which relies on the selective release of a family of proteins, referred to as small, acid-soluble spore proteins (SASPs). In this work, SASPs were selectively solubilized from Bacillus spores on the MALDI sample plate by using 10% TFA. Proteolytic digests of SASPs generated in situ from spores of B. subtilis 168, B. globigii, B. thuringiensis subs. Kurstaki HD-1, B. cereus T, and the nonpathogenic strain B. anthracis Sterne were prepared in 5-25 min by using trypsin immobilized on Agarose beads and subsequently analyzed by MALDI-TOFMS using a curved-field reflectron. Protein identification was obtained by partial sequencing of distinctive tryptic peptides from Bacillus spores via post-source decay analysis combined with genome-based database searches by Mascot Sequence Query. Various unique SASPs were identified, allowing the characterization of Bacillus species by obtaining sequence-specific information on single peptides. The applicability of this approach for the rapid identification of Bacillus species was further established by analyzing spore mixtures.
Warscheid
Bettina
B
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA. bwarscheid@hotmail.com
Fenselau
Catherine
C
D000595:Amino Acid Sequence; D001407:Bacillus / Q000737:chemistry / Q000302:isolation & purification*; D001408:Bacillus anthracis / 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
D001426:Bacterial Proteins; D010446:Peptide Fragments; D014269:Trifluoroacetic Acid; D014357:Trypsin