title: Photoleucine Survives Backbone Cleavage by Electron Transfer Dissociation. A Near-UV Photodissociation and Infrared Multiphoton Dissociation Action Spectroscopy Study.
abstract: We report a combined experimental and computational study aimed at elucidating the structure of N-terminal fragment ions of the c type produced by electron transfer dissociation of photo-leucine (L*) peptide ions GL*GGKX. The c 4 ion from GL*GGK is found to retain an intact diazirine ring that undergoes selective photodissociation at 355 nm, followed by backbone cleavage. Infrared multiphoton dissociation action spectra point to the absence in the c 4 ion of a diazoalkane group that could be produced by thermal isomerization of vibrationally hot ions. The c 4 ion from ETD of GL*GGK is assigned an amide structure by a close match of the IRMPD action spectrum and calculated IR absorption. The energetics and kinetics of c 4 ion dissociations are discussed. Graphical Abstract ᅟ.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195-1700, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Shaffer
authors.affiliation: FELIX Laboratory, Radboud University Nijmegen, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED, Nijmegen, The Netherlands.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Martens
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195-1700, USA.|Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Aleš
authors.initials: A
authors.lastname: Marek
authors.affiliation: FELIX Laboratory, Radboud University Nijmegen, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED, Nijmegen, The Netherlands.|van't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098XH, Amsterdam, Science Park 908, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Oomens
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195-1700, USA. turecek@chem.washington.edu.
authors.forename: František
authors.initials: F
authors.lastname: Tureček
keywords: Electron transfer dissociation; Infrared multiphoton dissociation action spectroscopy; Near-UV photodissociation; Peptide ions; Photoleucine label