title: An Artificial Enzyme Made by Covalent Grafting of an Fe(II) Complex into β-Lactoglobulin: Molecular Chemistry, Oxidation Catalysis, and Reaction-Intermediate Monitoring in a Protein.
abstract: An artificial metalloenzyme based on the covalent grafting of a nonheme Fe(II) polyazadentate complex into bovine β-lactoglobulin has been prepared and characterized by using various spectroscopic techniques. Attachment of the Fe(II) catalyst to the protein scaffold is shown to occur specifically at Cys121. In addition, spectrophotometric titration with cyanide ions based on the spin-state conversion of the initial high spin (S=2) Fe(II) complex into a low spin (S=0) one allows qualitative and quantitative characterization of the metal center's first coordination sphere. This biohybrid catalyst activates hydrogen peroxide to oxidize thioanisole into phenylmethylsulfoxide as the sole product with an enantiomeric excess of up to 20 %. Investigation of the reaction between the biohybrid system and H2 O2 reveals the generation of a high spin (S=5/2) Fe(III) (η(2) -O2 ) intermediate, which is proposed to be responsible for the catalytic sulfoxidation of the substrate.
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France).
authors.forename: Charlotte
authors.initials: C
authors.lastname: Buron
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France).
authors.forename: Katell
authors.initials: K
authors.lastname: Sénéchal-David
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France).
authors.forename: Rémy
authors.initials: R
authors.lastname: Ricoux
authors.affiliation: Centre de recherche de Gif, Institut de Chimie des Substances Naturelles CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France).
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Le Caër
authors.affiliation: Centre de recherche de Gif, Institut de Chimie des Substances Naturelles CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex (France).
authors.forename: Vincent
authors.initials: V
authors.lastname: Guérineau
authors.affiliation: Institut Universitaire de Technologie d'Orsay, Université Paris Sud, 91405, Orsay CEDEX (France).
authors.forename: Philippe
authors.initials: P
authors.lastname: Méjanelle
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France).
authors.forename: Régis
authors.initials: R
authors.lastname: Guillot
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France).
authors.forename: Christian
authors.initials: C
authors.lastname: Herrero
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France). jean-pierre.mahy@u-psud.fr.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Mahy
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France). frederic.banse@u-psud.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Banse
mesh_terms: D000818:Animals; D001372:Aza Compounds / Q000737:chemistry*; D055162:Biocatalysis; D002384:Catalysis; D002417:Cattle; D056831:Coordination Complexes / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D010084:Oxidation-Reduction; D011506:Proteins / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001372:Aza Compounds; D056831:Coordination Complexes; D005296:Ferrous Compounds; D007782:Lactoglobulins; D011506:Proteins; D006861:Hydrogen Peroxide
keywords: bioinorganic chemistry; coordination compounds; enzyme catalysis; enzyme models; iron