title: Toluene monooxygenase from the fungus Cladosporium sphaerospermum.
abstract: Assimilation of toluene by Cladosporium sphaerospermum is initially catalyzed by toluene monooxygenase (TOMO). TOMO activity was induced by adding toluene to a glucose-pregrown culture of C. sphaerospermum. The corresponding microsomal enzyme needed NADPH and O(2) to oxidize toluene and glycerol, EDTA, DTT, and PMSF for stabilization. TOMO activity was maximal at 35 degrees C and pH 7.5 and was inhibited by carbon monoxide, Metyrapone, and cytochrome c. TOMO preferred as substrates also other aromatic hydrocarbons with a short aliphatic side chain. Its reduced carbon monoxide difference spectrum showed a maximum at 451 nm. A substrate-induced Type I spectrum was observed on addition of toluene. These results indicated that TOMO is a cytochrome P450. TOMO and its corresponding reductase were eventually purified by a simultaneous purification revealing apparent molecular masses of 58 and 78 kDa, respectively.
authors.affiliation: Division of Industrial Microbiology, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands. dion.luykx@rivm.nl
authors.forename: Dion M A M
authors.initials: DM
authors.lastname: Luykx
authors.forename: Francesc X
authors.initials: FX
authors.lastname: Prenafeta-Boldú
authors.forename: Jan A M
authors.initials: JA
authors.lastname: de Bont
mesh_terms: D001673:Biodegradation, Environmental; D002248:Carbon Monoxide / Q000378:metabolism; D002963:Cladosporium / Q000737:chemistry* / Q000145:classification / Q000201:enzymology* / Q000254:growth & development; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008861:Microsomes / Q000737:chemistry / Q000201:enzymology; D008970:Molecular Weight; D010088:Oxidoreductases / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D010105:Oxygenases / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D013696:Temperature; D014050:Toluene / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D014050:Toluene; D002248:Carbon Monoxide; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D010105:Oxygenases; C114360:toluene 2-xylene monooxygenase