title: Stepwise oxygenations of toluene and 4-nitrotoluene by a fungal peroxygenase.
abstract: Fungal peroxygenases have recently been shown to catalyze remarkable oxidation reactions. The present study addresses the mechanism of benzylic oxygenations catalyzed by the extracellular peroxygenase of the agaric basidiomycete Agrocybe aegerita. The peroxygenase oxidized toluene and 4-nitrotoluene via the corresponding alcohols and aldehydes to give benzoic acids. The reactions proceeded stepwise with total conversions of 93% for toluene and 12% for 4-nitrotoluene. Using H(2)(18)O(2) as the co-substrate, we show here that H(2)O(2) is the source of the oxygen introduced at each reaction step. A. aegerita peroxygenase resembles cytochromes P450 and heme chloroperoxidase in catalyzing benzylic hydroxylations.
authors.affiliation: Unit of Environmental Biotechnology, International Graduate School of Zittau, Markt 23, Zittau, Germany. kinne@ihi-zittau.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Kinne
authors.forename: Christian
authors.initials: C
authors.lastname: Zeisig
authors.forename: René
authors.initials: R
authors.lastname: Ullrich
authors.forename: Gernot
authors.initials: G
authors.lastname: Kayser
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Hammel
authors.forename: Martin
authors.initials: M
authors.lastname: Hofrichter
mesh_terms: D055362:Agrocybe / Q000201:enzymology*; D001711:Biotransformation; D002384:Catalysis; D006861:Hydrogen Peroxide / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction; D014050:Toluene / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D014050:Toluene; D006861:Hydrogen Peroxide; C017572:4-nitrotoluene; D006899:Mixed Function Oxygenases; C022333:peroxygenase