title: Aromatic nitroreductase from the basidiomycete Phanerochaete chrysosporium.
abstract: A membrane-associated aromatic nitroreductase activity was identified in cell-free extracts of the lignin-degrading fungus Phanerochaete chrysosporium. The enzyme catalyzed the nitro group reduction of 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, 1-chloro-2,4-dinitrobenzene, and 2,4-dichloro-1-nitrobenzene. The corresponding hydroxylamines and/or amines were identified as reaction products by HPLC and/or GC-MS. 1-Nitroso-3-nitrobenzene and 1-hydroxylamino-3-nitrobenzene also were reduced by the enzyme, suggesting they were intermediates in the reaction. The enzyme required NAD(P)H as a cosubstrate and the optimal pH and temperature for the reaction were 6.5 and 50 degrees C, respectively. Enzyme activity was not observed in the presence of molecular oxygen. The membrane-associated enzyme could be solubilized with the nonionic detergent Triton X-100.
authors.affiliation: Department of Chemistry, Biochemistry, and Molecular Biology, Oregon Graduate Institute of Science & Technology, Portland 97291-1000.
authors.forename: S
authors.initials: S
authors.lastname: Rieble
authors.forename: D K
authors.initials: DK
authors.lastname: Joshi
authors.forename: M H
authors.initials: MH
authors.lastname: Gold
mesh_terms: D001487:Basidiomycota / Q000201:enzymology*; D001673:Biodegradation, Environmental; D002384:Catalysis; D004136:Dinitrobenzenes / Q000378:metabolism; D009578:Nitrobenzenes / Q000378:metabolism; D009601:Nitroreductases / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D004136:Dinitrobenzenes; D009578:Nitrobenzenes; C016403:2,4-dinitrotoluene; D009601:Nitroreductases