title: Purification and properties of nitroalkane-oxidizing enzyme from Hansenula mrakii.
abstract: A nitroalkane-oxidizing enzyme was purified about 1,300-fold from a cell extract of Hansenula mrakii grown in a medium containing nitroethane as the sole nitrogen source by ammonium sulfate fractionation, diethylaminoethyl-cellulose column chromatography, hydroxyapatite column chromatography, and Bio-Gel P-150 column chromatography. The enzyme was shown to be homogeneous upon acrylamide gel electrophoresis and ultracentrifugation. The enzyme exhibits absorption maxima at 274, 370, 415, and 440 nm and a shoulder at 470 nm. Balance studies showed that 2 mol of 2-nitropropane is converted into an equimolar amount of acetone and nitrite with the consumption of 1 mol of oxygen. Hydrogen peroxide is not formed in the enzyme reaction. In addition to 2-nitropropane, 1-nitropropane and nitroethane are oxidatively dentrified by the enzyme, but nitromethane is inert to the enzyme. The nitroalkanes are not oxidized under anaerobic conditions.
mesh_terms: D000096:Acetone / Q000378:metabolism; D000332:Aerobiosis; D000645:Ammonium Sulfate; D001203:Ascomycota / Q000201:enzymology*; D005591:Chemical Fractionation; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004980:Ethane / Q000031:analogs & derivatives* / Q000378:metabolism; D006882:Hydroxyapatites; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism; D010101:Oxygen Consumption; D010843:Pichia / Q000201:enzymology* / Q000378:metabolism; D011407:Propane / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D006882:Hydroxyapatites; D009573:Nitrites; D000096:Acetone; D010088:Oxidoreductases; D004980:Ethane; D000645:Ammonium Sulfate; D011407:Propane