Cholest-4-en-3-one-delta 1-dehydrogenase, a flavoprotein catalyzing the second step in anoxic cholesterol metabolism.

ABSTRACT: The anoxic metabolism of cholesterol was studied in the denitrifying bacterium Sterolibacterium denitrificans, which was grown with cholesterol and nitrate. Cholest-4-en-3-one was identified before as the product of cholesterol dehydrogenase/isomerase, the first enzyme of the pathway. The postulated second enzyme, cholest-4-en-3-one-Delta(1)-dehydrogenase, was partially purified, and its N-terminal amino acid sequence and tryptic peptide sequences were determined. Based on this information, the corresponding gene was amplified and cloned and the His-tagged recombinant protein was overproduced, purified, and characterized. The recombinant enzyme catalyzes the expected Delta(1)-desaturation (cholest-4-en-3-one to cholesta-1,4-dien-3-one) under anoxic conditions. It contains approximately one

SUBMITTER: Chiang YR 

PROVIDER: S-EPMC2223216 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature