title: Do b-ions occur from vibrational excitation upon H-desorption in electron capture dissociation?
abstract: Electron capture dissociation (ECD) has recently been shown in some cases to produce abundant N-terminal b-ion peptide fragments. These product ions are usually only observed when activation occurs via vibrational excitation as in collision-induced dissociation (CID). Here, we show that occurrence of b-ions in the ECD spectra of synthetic peptides are correlated with low gas-phase basicity and that the observed b-ion fragments are N-terminal products. Furthermore, all ECD spectra containing b-ions also had abundant losses of hydrogen and ammonia from the charge-reduced species.
authors.affiliation: Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. kfh@chem.sdu.dk
authors.forename: Kim F
authors.initials: KF
authors.lastname: Haselmann
authors.forename: Marcel
authors.initials: M
authors.lastname: Schmidt
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D004579:Electron Transport; D004735:Energy Transfer; D007477:Ions; D010449:Peptide Mapping / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014732:Vibration
chemical_list: D007477:Ions; D010455:Peptides; D000641:Ammonia