A novel NADPH-dependent carbonyl reductase of Candida macedoniensis: purification and characterization.
A novel NADPH-dependent carbonyl reductase was purified to homogeneity from the soluble fraction of a cell extract of Candida macedoniensis AKU 4588. The enzyme catalyzes not only the reduction of quinones, but also the reduction of aromatic aldehydes, conjugated polyketones, 2'-ketopantothenate esters, and 4-chloro-3-oxobutanoate esters. The enzyme shows absolute specificity for NADPH as a coenzyme and also shows quite high affinity toward NADPH (Km less than 5 microM). The apparent Km values for menadione and p-toluquinone are 167 and 180 microM, respectively. The enzyme is not a flavoprotein and is a monomer protein with a relative molecular mass of 45,000. Dicoumarol, quercetin, and some sulfhydryl reagents inhibit the enzyme activity.
Kataoka
M
M
Department of Agricultural Chemistry, Kyoto University, Japan.
Doi
Y
Y
Sim
T S
TS
Shimizu
S
S
Yamada
H
H
D000429:Alcohol Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism*; D000449:Aldehyde Reductase; D000074408:Aldo-Keto Reductases; D000595:Amino Acid Sequence; D002175:Candida / Q000201:enzymology*; D002850:Chromatography, Gel / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D013816:Thermodynamics
D000429:Alcohol Oxidoreductases; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase