title: UV/Vis Action Spectroscopy and Structures of Tyrosine Peptide Cation Radicals in the Gas Phase.
abstract: We report the first application of UV/Vis photodissociation action spectroscopy for the structure elucidation of tyrosine peptide cation radicals produced by oxidative intramolecular electron transfer in gas-phase metal complexes. Oxidation of Tyr-Ala-Ala-Ala-Arg (YAAAR) produces Tyr-O radicals by combined electron and proton transfer involving the phenol and carboxyl groups. Oxidation of Ala-Ala-Ala-Tyr-Arg (AAAYR) produces a mixture of cation radicals involving electron abstraction from the Tyr phenol ring and N-terminal amino group in combination with hydrogen-atom transfer from the Cα positions of the peptide backbone.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Emilie
authors.initials: E
authors.lastname: Viglino
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Shaffer
authors.affiliation: Department of Chemistry, University of Washington, Seattle, WA, 98195, USA. turecek@chem.washington.edu.
authors.forename: František
authors.identifier: 0000-0001-7321-7858
authors.initials: F
authors.lastname: Tureček
keywords: UV/Vis spectroscopy; copper complexes; electron transfer; gas-phase chemistry; peptides