title: Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates.
abstract: FeIII-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII-hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases.
authors.affiliation: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors.forename: Apparao
authors.initials: A
authors.lastname: Draksharapu
authors.affiliation: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors.forename: Davide
authors.initials: D
authors.lastname: Angelone
authors.affiliation: Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK).
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Quesne
authors.affiliation: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors.forename: Sandeep K
authors.initials: SK
authors.lastname: Padamati
authors.affiliation: Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus de Montilivi, Girona 17071 (Spain); Serveis Tècnics de Recerca (STR), Universitat de Girona, Parc Científic i Tecnològic, E-17003 Girona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Gómez
authors.affiliation: Catexel Ltd., BioPartner Center Leiden, Galileiweg 8, 2333 BD Leiden (The Netherlands).
authors.forename: Ronald
authors.initials: R
authors.lastname: Hage
authors.affiliation: Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus de Montilivi, Girona 17071 (Spain).
authors.forename: Miquel
authors.initials: M
authors.lastname: Costas
authors.affiliation: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors.forename: Wesley R
authors.initials: WR
authors.lastname: Browne
authors.affiliation: Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK).
authors.forename: Sam P
authors.initials: SP
authors.lastname: de Visser
keywords: EPR‐Spektroskopie; Eisen; Hypochlorit; Metalloenzyme; Raman‐Spektroskopie