Characterization of NADP+: 3 beta-hydroxysteroid dehydrogenase from microsomes of rat liver.
A NADP(+)-dependent 3 beta-hydroxysteroid dehydrogenase activity was localized in the microsomal fraction of rat liver. This enzyme was solubilized and separated completely from 3 alpha-hydroxysteroid dehydrogenase by Matrex red A column chromatography. Partially purified 3 beta-hydroxysteroid dehydrogenase catalyzed the oxidation and reduction between the 3 beta-hydroxyl and 3-ketonic group of steroids or bile acids having no double bond in the A/B ring, but was inactive toward 3 alpha-hydroxyl group. The enzyme required NADP+ for oxidation and NADPH for reduction. The activity was inhibited by p-chloromercuribenzoic acid or p-chloromercuribenzenesulfonic acid at the concentration of 10(-4) M. The molecular weight of the enzyme was estimated to be about 43,000 by Sephadex G-200 column chromatography. From these results, it is concluded that the enzyme is a new type of microsomal NADP+:3 beta-hydroxysteroid dehydrogenase.
Akao
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T
Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Akao
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Kobashi
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D015096:3-Hydroxysteroid Dehydrogenases / Q000737:chemistry / Q000378:metabolism*; D002731:4-Chloromercuribenzenesulfonate / Q000494:pharmacology; D000818:Animals; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002855:Chromatography, Thin Layer; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D009243:NAD / Q000494:pharmacology*; D009249:NADP / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D020245:p-Chloromercuribenzoic Acid
D002729:Chloromercuribenzoates; D009243:NAD; D009249:NADP; D020245:p-Chloromercuribenzoic Acid; D002731:4-Chloromercuribenzenesulfonate; D015096:3-Hydroxysteroid Dehydrogenases