Probing peptide fragment ion structures by combining sustained off-resonance collision-induced dissociation and gas-phase H/D exchange (SORI-HDX) in Fourier transform ion-cyclotron resonance (FT-ICR) instruments.
The usefulness of gas-phase H/D exchange is demonstrated to probe heterogeneous fragment and parent ion populations. Singly and multiply protonated peptides/proteins were fragmented by using sustained off-resonance irradiation collision-induced dissociation (SORI-CID). The fragments and the surviving precursor ions then all undergo H/D exchange in the gas-phase with either D(2)O or CD(3)OD under the same experimental conditions. Usually, 10 to 60 s of reaction time is adequate to monitor characteristic differences in the H/D exchange kinetic rates. These differences are then correlated to isomeric ion structures. The SORI-HDX method can be used to rapidly test fragment ion structures and provides useful insights into peptide fragmentation mechanisms.
Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA. asomogyi@u.arizona.edu
Arpád
A
Somogyi
D017357:Cyclotrons; D003903:Deuterium; D005583:Fourier Analysis; D006859:Hydrogen; D007477:Ions; D015394:Molecular Structure; D010446:Peptide Fragments / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
D007477:Ions; D010446:Peptide Fragments; D006859:Hydrogen; D003903:Deuterium