An Artificial Enzyme Made by Covalent Grafting of an FeII Complex into β‐Lactoglobulin: Molecular Chemistry,Oxidation Catalysis,and Reaction‐Intermediate Monitoring in a Protein |
| |
| Authors: | Charlotte Buron Dr Katell Sénéchal‐David Dr Rémy Ricoux Jean‐Pierre Le Caër Vincent Guérineau Dr Philippe Méjanelle Dr Régis Guillot Dr Christian Herrero Prof Jean‐Pierre Mahy Prof Frédéric Banse |
| |
| Affiliation: | 1. Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, CNRS, 91405, Orsay CEDEX (France);2. Centre de recherche de Gif, Institut de Chimie des Substances Naturelles CNRS, Avenue de la Terrasse, 91198 Gif‐sur‐Yvette Cedex (France);3. Institut Universitaire de Technologie d'Orsay, Université Paris Sud, 91405, Orsay CEDEX (France) |
| |
| Abstract: | An artificial metalloenzyme based on the covalent grafting of a nonheme FeII polyazadentate complex into bovine β‐lactoglobulin has been prepared and characterized by using various spectroscopic techniques. Attachment of the FeII 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) FeII 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 H2O2 reveals the generation of a high spin (S=5/2) FeIII(η2‐O2) intermediate, which is proposed to be responsible for the catalytic sulfoxidation of the substrate. |
| |
| Keywords: | bioinorganic chemistry coordination compounds enzyme catalysis enzyme models iron |
|
|
