Referenced in: none

Automatically associated channels: Kir2.3

Title: Laser-induced dissociation of singly protonated peptides at 193 and 266 nm within a hybrid linear ion trap mass spectrometer.

Authors: Cheuk-Kuen Lai, Dominic C M Ng, H F Pang, J C Yves Le Blanc, James W Hager, De-Cai Fang, A S-C Cheung, Ivan K Chu

Journal, date & volume: Rapid Commun. Mass Spectrom., 2013 May 30 , 27, 1119-27

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23592116

Abstract
We implemented, for the first time, laser-induced dissociation (LID) within a modified hybrid linear ion trap mass spectrometer, QTrap, while preserving the original scanning capabilities and routine performance of the instrument.Precursor ions of interest were mass-selected in the first quadrupole (Q1), trapped in the radiofrequency-only quadrupole (q2), photodissociated under irradiation with a 193- or 266-nm laser beam in the third quadrupole (q3), and mass-analyzed using the linear ion trap.LID of singly charged protonated peptides revealed, in addition to conventional amide-bond cleavages, preferential fragmentation at Cα -C/N-Cα bonds of the backbone as well as at the Cα -Cβ /Cβ -Cγ bonds of the side-chains. The LID spectra of [M+H](+) featured product ions that were very similar to the observed radical-induced fragmentations in the CID spectra of analogous odd-electron radical cations generated through dissociative electron-transfer in metal-ligand-peptide complexes or through laser photolysis of iodopeptides.LID of [M+H](+) ions results in fragmentation channels that are comparable with those observed upon the CID of M(•+) ions, with a range of fascinating radical-induced fragmentations.