title: Hydroxylation of naphthalene by aromatic peroxygenase from Agrocybe aegerita proceeds via oxygen transfer from H2O2 and intermediary epoxidation.
abstract: Agrocybe aegerita peroxidase/peroxygenase (AaP) is an extracellular fungal biocatalyst that selectively hydroxylates the aromatic ring of naphthalene. Under alkaline conditions, the reaction proceeds via the formation of an intermediary product with a molecular mass of 144 and a characteristic UV absorption spectrum (A(max) 210, 267, and 303 nm). The compound was semistable at pH 9 but spontaneously hydrolyzed under acidic conditions (pH<7) into 1-naphthol as major product and traces of 2-naphthol. Based on these findings and literature data, we propose naphthalene 1,2-oxide as the primary product of AaP-catalyzed oxygenation of naphthalene. Using (18)O-labeled hydrogen peroxide, the origin of the oxygen atom transferred to naphthalene was proved to be the peroxide that acts both as oxidant (primary electron acceptor) and oxygen source.
authors.affiliation: Unit of Environmental Biotechnology, International Graduate School of Zittau, Zittau, Germany. kluge@ihi-zittau.de
authors.forename: Martin
authors.initials: M
authors.lastname: Kluge
authors.forename: René
authors.initials: R
authors.lastname: Ullrich
authors.forename: Christoph
authors.initials: C
authors.lastname: Dolge
authors.forename: Katrin
authors.initials: K
authors.lastname: Scheibner
authors.forename: Martin
authors.initials: M
authors.lastname: Hofrichter
mesh_terms: D055362:Agrocybe / Q000201:enzymology*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006900:Hydroxylation; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009281:Naphthalenes / Q000378:metabolism*; D009284:Naphthols / Q000378:metabolism; D010103:Oxygen Isotopes / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D009281:Naphthalenes; D009284:Naphthols; D010103:Oxygen Isotopes; C031721:naphthalene; C042033:naphthalene 1,2-oxide; C029350:1-naphthol; D006861:Hydrogen Peroxide; D006899:Mixed Function Oxygenases; C022333:peroxygenase; C028405:2-naphthol