Cholesterol oxidase: biochemistry and structural features

摘要: Cholesterol oxidases are bifunctional flavoenzymes that catalyze the oxidation of steroid substrates which have a hydroxyl group at 3β position ring system. The enzyme is found, in wide range bacterial species, two forms: one with FAD cofactor bound noncovalently to enzyme; and linked covalently protein. Here we discuss, compare contrast salient biochemical properties forms enzyme. Specifically, structural features discussed affect redox potentials flavin cofactor, chemical mechanism substrate dehydrogenation by active-center amino acid residues, kinetic parameters both types enzymes reactivity reduced molecular dioxygen. presence tunnel proposed serve access dioxygen active site mechanisms its control ‘gate’ formed residues highlighted.