Bacillus Spore Identification via Proteolytic Peptide Mapping with a Miniaturized MALDI TOF Mass Spectrometer

Abstract

An approach is tested here as a rapid screening method for Bacillus spore species employing bacterial peptide analysis with a miniaturized MALDI TOF mass spectrometer. A limited set of tryptic peptides was generated in situ following selective solubilization of the small, acid-soluble protein family (SASP) from spore samples on the MALDI sample holder. To facilitate species identification, a compact database was created comprising masses of the tryptic cleavage products generated in silico from all Bacillus and Clostridium SASPs whose sequences are available in public databases. Experimental measurements were matched against the custom-made database, and a published statistical model was then used to evaluate the probability of false identifications.

Toward Universal Flavivirus Identification by Mass Cataloging

“…Thus, it is presently feasible to analyze a single clinical sample in approximately 1.5 hours or less with results similar to those shown here, and with additional informatics work extremely specific genotyping of any given Flavivirus should be possible. Moreover, all the steps in the protocol are amenable to high-throughput automated im- [27][28][29][30] it will soon be possible to take such cultureindependent molecular assays to remote locations to improve greatly the response time for epidemiological and clinical intervention.…”

Bioinformatics for Flexibility, Reliability, and Mixture Analysis of Intact Microorganisms

“…These peptide databases can be interrogated to provide identifications of microorganisms by algorithms analogous to those developed to search protein databases for suites of protein mass matches. 80,81 This strategy requires a more complex system for sample processing; however, it engages the advantages of improved mass accuracy and better sensitivity that derive from working with lower mass ions. Peptide maps from protein mixtures have been demonstrated to provide reliable identifications of microorganisms that are reasonably pure.…”

“…Peptide maps from protein mixtures have been demonstrated to provide reliable identifications of microorganisms that are reasonably pure. [79][80][81] As is the case with identifications based on protein molecular masses, it appears that the use of tryptic or other peptide masses as the basis for identification is extended with difficulty to mixtures of microorganisms. This reflects unpredictable suppression.…”

Identifying bacterial species using CE–MS and SEQUEST with an empirical scoring function

“…Proteins that have been extracted from microbial samples can be digested by enzymes; the sequence information of the peptides, obtained by MS/MS, can then be utilized to identify the proteins and deduce the microorganism's source through a proteome database search [23][24][25][26][27][28][29][30]. Recently, the authors' group reported approaches that use the selective proteotypic-peptide analysis (SPA) of protein digests that have been separated through CE to accurately identify bacterial mixtures [31][32][33].…”