Oxidative dechlorination of halogenated phenols catalyzed by two distinct enzymes: Horseradish peroxidase and dehaloperoxidase.
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.
Szatkowski
Lukasz
L
Technical University of Lodz, Faculty of Chemistry, Institute of Applied Radiation Chemistry, Zeromskiego 116, 90-924 Lodz, Poland.
Thompson
Matthew K
MK
Kaminski
Rafal
R
Franzen
Stefan
S
Dybala-Defratyka
Agnieszka
A
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*
D006219:Halogens; D010636:Phenols; D006735:Horseradish Peroxidase; D010544:Peroxidases