title: Prompt and slow electron-detachment-dissociation/electron-photodetachment-dissociation of a 21-mer peptide.
abstract: Electron detachment dissociation (EDD) and electron photodetachment dissociation (EPD) are relatively new dissociation methods that involve electron detachment followed by radical-driven dissociation from multiply deprotonated species. EDD yields prompt dissociation whereas only electron detachment is obtained by EPD; subsequent vibrational activation of the charge-reduced radical anion is required to obtain the product ions. Herein, the fragmentation patterns that were obtained by EDD and by vibrational activation of the charge-reduced radical anions that were produced through EDD or EPD (activated-EDD and activated-EPD) were compared. The observed differences were related to the dissociation kinetics and/or the contribution of electron-induced dissociation (EID). Time-resolved double-resonance experiments were performed to measure the dissociation rate constants of the EDD product ions. Differences in the formation kinetics were revealed between the classical EDD/EPD 'a(⋅)(i)/''x(j) complementary ions and some 'a(⋅)(i)/c(i)/'''z(⋅)(j) product ions, which were produced with slower dissociation rate constants, owing to the presence of specific neighbouring side chains. A new fragmentation pathway is proposed for the formation of the slow-kinetics 'a(⋅)(i) ions.
authors.affiliation: Parisian Institute of Molecular Chemistry, UMR 7201 CNRS-University Pierre & Marie Curie, Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Pérot-Taillandier
authors.forename: Séverine
authors.initials: S
authors.lastname: Zirah
authors.forename: Quentin
authors.initials: Q
authors.lastname: Enjalbert
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Antoine
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lemoine
authors.forename: Philippe
authors.initials: P
authors.lastname: Dugourd
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rebuffat
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Tabet
authors.forename: Carlos
authors.initials: C
authors.lastname: Afonso
mesh_terms: D000595:Amino Acid Sequence; D004583:Electrons; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes
chemical_list: D010455:Peptides