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The haloperoxidase of the agaric fungus Agrocybe aegerita hydroxylates toluene and naphthalene
Author(s) -
Ullrich René,
Hofrichter Martin
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.10.014
Subject(s) - chemistry , toluene , naphthalene , biotransformation , enzyme , phenol , benzoic acid , organic chemistry , medicinal chemistry , stereochemistry
The mushroom Agrocybe aegerita secretes a peroxidase (AaP) that catalyzes halogenations and hydroxylations. Phenol was brominated to 2‐ and 4‐bromophenol (ratio 1:4) and chlorinated to a lesser extent to 2‐chlorophenol. The purified enzyme was found to oxidize toluene via benzyl alcohol and benzaldehyde into benzoic acid. A second fraction of toluene was hydroxylated to give p ‐cresol as well as o ‐cresol and methyl‐ p ‐benzoquinone. The UV–Vis absorption spectrum of purified AaP showed high similarity to a resting state cytochrome P450 with the Soret band at 420 nm and additional maxima at 278, 358, 541 and 571 nm; the AaP CO‐complex had a distinct absorption maximum at 445 nm that is characteristic for heme‐thiolate proteins. AaP regioselectively hydroxylated naphthalene to 1‐naphthol and traces of 2‐naphthol (ratio 36:1). H 2 O 2 was necessarily required for AaP function and hence the hydroxylations catalyzed by AaP can be designated as peroxygenation and the enzyme as an extracellular peroxygenase.