title: Microbial transformations of steroids--X. Cytochromes P-450 11 alpha-hydroxylase and C17-C20 lyase and a 1-ene dehydrogenase transform steroids in Nectria haematococca.
abstract: Nectria haematococca contains four enzymes that metabolise exogenous steroids. Two of these are microsomal cytochromes P-450 which act sequentially on progesterone producing firstly, by side-chain cleavage, the C19 steroid androstenedione (C17-C20 lyase), and then, in a subsequent set of transformations, 11 alpha-hydroxylated derivatives (11 alpha-hydroxylase). Two other conversions occur after side-chain cleavage. Unsaturation, in the form of a double bond at C1-C2, is introduced into the A ring by a catalytically self-sufficient microsomal 1-ene dehydrogenase. This enzyme is specific for C19 substrates. A C17-specific oxidoreductase is also involved in the production of androstenedione and testosterone from progesterone. The lyase, 11 alpha-hydroxylase and 1-ene dehydrogenase were purified to homogeneity.
authors.affiliation: Department of Biochemistry, Queen Mary and Westfield College, Mile End Road, London, UK.
authors.forename: F
authors.initials: F
authors.lastname: Ahmed
authors.forename: R A
authors.initials: RA
authors.lastname: Williams
authors.forename: K E
authors.initials: KE
authors.lastname: Smith
mesh_terms: D000735:Androstenedione / Q000378:metabolism; D001711:Biotransformation; D005670:Fusarium / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D010088:Oxidoreductases / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism*; D013250:Steroid Hydroxylases / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone; D000735:Androstenedione; D011374:Progesterone; D010088:Oxidoreductases; D013250:Steroid Hydroxylases; D013254:Steroid 17-alpha-Hydroxylase; C026444:1-ene-dehydrogenase