title: Oxidative dechlorination of halogenated phenols catalyzed by two distinct enzymes: Horseradish peroxidase and dehaloperoxidase.
abstract: The mechanism of the dehalogenation step catalyzed by dehaloperoxidase (DHP) from Amphitrite ornata, an unusual heme-containing protein with a globin fold and peroxidase activity, has remarkable similarity with that of the classical heme peroxidase, horseradish peroxidase (HRP). Based on quantum mechanical/molecular mechanical (QM/MM) modeling and experimentally determined chlorine kinetic isotope effects, we have concluded that two sequential one electron oxidations of the halogenated phenol substrate leads to a cationic intermediate that strongly resembles a Meisenheimer intermediate - a commonly formed reactive complex during nucleophilic aromatic substitution reactions especially in the case of arenes carrying electron withdrawing groups.
authors.affiliation: Technical University of Lodz, Faculty of Chemistry, Institute of Applied Radiation Chemistry, Zeromskiego 116, 90-924 Lodz, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Szatkowski
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Thompson
authors.forename: Rafal
authors.initials: R
authors.lastname: Kaminski
authors.forename: Stefan
authors.initials: S
authors.lastname: Franzen
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Dybala-Defratyka
mesh_terms: D000818:Animals; D031215:Armoracia / Q000201:enzymology*; D054879:Halogenation; D006219:Halogens / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism*; D011077:Polychaeta / Q000201:enzymology*
chemical_list: D006219:Halogens; D010636:Phenols; D006735:Horseradish Peroxidase; D010544:Peroxidases