title: Lyophilized Clostridium perfringens 3 alpha- and Clostridium bifermentans 7 alpha-hydroxysteroid dehydrogenases: two new stable enzyme preparations for routine bile acid analysis.
abstract: Preparations of 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) from Clostridium perfringens were successfully lyophilized into a stable powder form. Purification of the enzyme was achieved using triazine dye affinity chromatography. C. perfringens 3 alpha-hydroxysteroid dehydrogenase was purified 24-fold using Reactive Red 120 (Procion Red) -cross-linked agarose (70% yield). Quantitative measurement of bile acids with the purified enzymes, 3 alpha-hydroxysteroid dehydrogenase and 7 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.159) from Clostridium bifermentans (strain F-6), was achieved spectrophotometrically. Standard curves with chenodeoxycholic acid (CDC) and cholic acid were linear within a concentration range of 20-100 microM. Analysis of mixtures of ursodeoxycholic acid and CDC showed the additive nature of the 3 alpha-hydroxysteroid dehydrogenase and showed also that 7 alpha-hydroxyl groups were independently quantified by the 7 alpha-hydroxysteroid dehydrogenase. Bile acids in Folch extracts of human bile samples were measured using purified preparations of Pseudomonas testosteroni 3 alpha-hydroxysteroid dehydrogenase, C. perfringens 3 alpha-hydroxysteroid dehydrogenase, Escherichia coli 7 alpha-hydroxysteroid dehydrogenase and C. bifermentans (strain F-6) 7 alpha-hydroxysteroid dehydrogenase. Statistical comparison validated the use of C. perfringens 3 alpha- and C. bifermentans 7 alpha-hydroxysteroid dehydrogenases for the quantification of bile acids in bile.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000302:isolation & purification / Q000592:standards; D001646:Bile / Q000201:enzymology; D001647:Bile Acids and Salts / Q000032:analysis*; D003016:Clostridium perfringens / Q000201:enzymology*; D005612:Freeze Drying; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000302:isolation & purification / Q000592:standards; D007202:Indicators and Reagents; D012015:Reference Standards
chemical_list: D001647:Bile Acids and Salts; D007202:Indicators and Reagents; D015096:3-Hydroxysteroid Dehydrogenases; D006913:Hydroxysteroid Dehydrogenases; C025376:7 alpha-hydroxysteroid dehydrogenase