title: Bile acid induction specificity of 7 alpha-dehydroxylase activity in an intestinal Eubacterium species.
abstract: The addition of cholic acid to growing cultures of Eubacterium species V.P.I. 12708 caused a 25 and 46-fold increase in 7 alpha-dehydroxylation activity using cell extracts or whole cell suspensions, respectively. Bile acid conversion rates using either [14C]-cholic acid or [14C]-chenodeoxycholic acid as substrates increased at approximately the same rate when either cholic or chenodeoxycholic acid was added to growing cultures as inducer. The induction of 7 alpha-dehydroxylase activity was highly specific requiring a free C-24-carboxyl group and an unhindered 7 alpha-hydroxy group on the B ring of the steroid nucleus. Unexpectedly, cholic acid also rapidly induced NADH:flavin oxidoreductase activity in growing cultures of this bacterium.
mesh_terms: D001647:Bile Acids and Salts / Q000378:metabolism / Q000494:pharmacology*; D002793:Cholic Acids / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000382:microbiology; D004790:Enzyme Induction; D005051:Eubacterium / Q000187:drug effects / Q000201:enzymology*; D005243:Feces / Q000382:microbiology; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases; D007700:Kinetics; D010088:Oxidoreductases; D013250:Steroid Hydroxylases / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D001647:Bile Acids and Salts; D002793:Cholic Acids; D010088:Oxidoreductases; D006913:Hydroxysteroid Dehydrogenases; C025376:7 alpha-hydroxysteroid dehydrogenase; D013250:Steroid Hydroxylases