title: Steroid oxidoreductase activity of alcohol dehydrogenases from horse, rat, and human liver.
abstract: Alcohol dehydrogenase from horse (isoenzyme SS and ES, but not EE), rat and human liver were found to catalyze the NAD-dependent oxidation of 3beta-hydroxy groups in 5alpha- and 5beta-steroids of the C19, C21, and C24 series. The enzymes from horse and rat liver were more active on 5beta-than on 5alpha-steroids. This difference was most marked with the enzyme from rat liver, especially with 3beta-hydroxyandrostan-17-ones and 3beta-hydroxypregnan-20-ones as substrates. The Km of isoenzyme ES from horse liver was lower for 3beta-hydroxy-5alpha-cholanoic acid (0.4 muM) than for 3beta-hydroxy-5beta-cholanoic acid (0.9 muM). 3alpha-Hydroxysteroids were not substrates for the enzymes from horse and rat liver. Human liver alcohol dehydrogenase had low affinity for 3beta-hydroxy-5alpha (and 5beta)-cholanoic acids, but oxidation could be clearly demonstrated by gas chromatographic analysis of the products.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D006736:Horses; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D013045:Species Specificity
chemical_list: D007527:Isoenzymes; D009243:NAD; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases