PNNL

Abstract

One of the grand challenges in the post-genomic era is the characterization of the proteins expressed in a cell under specific conditions, proteomics. A promising technology for high-throughput proteomics is mass spectrometry (MS). The accuracy and certainty of the determinations of peptide identities and abundances provided by MS are important to systems biology research. After a tryptically digested protein mixture is analyzed by LC-FTICR-MS, the observed masses and normalized elution times of the detected features are matched to theoretical masses and elution times of known peptides listed in a large database. Assuming a bivariate normal probability distribution on the uncertainties in the masses and the normalized elution times, the probability of a correct match is estimated for each peptide in the reference database using statistical classification methods.