title: Identification and spectroscopic characterization of nonheme iron(III) hypochlorite intermediates.
abstract: Fe(III)-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 Fe(III)-hypohalite intermediates of possible relevance to iron halogenases. We show that Fe(III)-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 Fe(III)-OCl, and ultimately Fe(IV)=O, species and provide indirect evidence for a short-lived Fe(II)-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases.
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors: Apparao
authors: A
authors: Draksharapu
authors: Davide
authors: D
authors: Angelone
authors: Matthew G
authors: MG
authors: Quesne
authors: Sandeep K
authors: SK
authors: Padamati
authors: Laura
authors: L
authors: Gómez
authors: Ronald
authors: R
authors: Hage
authors: Miquel
authors: M
authors: Costas
authors: Wesley R
authors: WR
authors: Browne
authors: Sam P
authors: SP
authors: de Visser
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D006997:Hypochlorous Acid / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D006997:Hypochlorous Acid
keywords: EPR spectroscopy; Raman spectroscopy; hypochlorite; iron; metalloenzymes