Combination of CID/SID Ion Activation Methods with H/D Exchange to Probe a Gas-Phase Intramolecular Rearrangement Process of Protonated Peptides

摘要

Tandem mass-spectrometry is a common tool used in proteomics for protein and peptide identification. Mass spectra obtained by using this technique are compared to spectra predicted by sequencing algorithms to make accurate peptide/protein identifications. Most tandem mass-spectra contain a number of fragment ion peaks that are not utilized by sequencing-algorithms. Sometimes these ions are abundant ions in the spectra. Because the origin of these fragments is not well understood, exploration of the formation of these fragmentation products could elevate the confidence level of identifying the correct sequence and minimize false-positive identification. This research focuses on the idea that peptides undergo complex rearrangement processes to form non-direct sequence ions that, if understood, could be beneficial in protein identification algorithms.