Prompt and Slow Electron‐Detachment‐Dissociation/Electron‐Photodetachment‐Dissociation of a 21‐Mer Peptide |
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Authors: | Dr Marie Pérot‐Taillandier Dr Séverine Zirah Quentin Enjalbert Dr Rodolphe Antoine Prof Jérôme Lemoine Dr Philippe Dugourd Prof Sylvie Rebuffat Prof Jean‐Claude Tabet Prof Carlos Afonso |
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Institution: | 1. Parisian Institute of Molecular Chemistry, UMR 7201 CNRS ‐ University Pierre & Marie Curie, Paris (France);2. Communication Molecules and Adaptation of Microorganisms, UMR 7245 CNRS ‐ National Museum of Natural History, Paris (France);3. UMR 5579 and UMR 5280, CNRS ‐ University of Lyon, Villeurbanne (France);4. UMR 6014 COBRA, INSA of Rouen, CNRS ‐ University of Rouen, 1 rue Tesnière, 76821 Mont Saint‐Aignan (France), Fax: (+33)?235‐522‐441 |
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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/′′xj complementary ions and some ′a.i/ci/′′′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. |
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Keywords: | electron detachment dissociation electron photodetachment dissociation kinetics mass spectrometry peptides |
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