EC Explorer

1.14.13.54

ketosteroid monooxygenase

a ketosteroid + NADPH + H⁺ + O₂ = a steroid ester/lactone + NADP⁺ + H₂O (general reaction);;(1) progesterone + NADPH + H⁺ + O₂ = testosterone acetate + NADP⁺ + H₂O;;(2) androstenedione + NADPH + H⁺ + O₂ = testololactone + NADP⁺ + H₂O;;(3) 17α-hydroxyprogesterone + NADPH + H⁺ + O₂ = androstenedione + acetate + NADP⁺ + H₂O

steroid-ketone monooxygenase, progesterone, NADPH₂:oxygen oxidoreductase (20-hydroxylating, ester-producing), 17α-hydroxyprogesterone, NADPH₂:oxygen oxidoreductase (20-hydroxylating, side-chain cleaving), androstenedione, NADPH₂:oxygen oxidoreductase (17-hydroxylating, lactonizing)

ketosteroid,NADPH:oxygen oxidoreductase (20-hydroxylating, ester-producing/20-hydroxylating, side-chain cleaving/17-hydroxylating, lactonizing)

9044-53-5

A single FAD-containing enzyme catalyses three types of monooxygenase (Baeyer-Villiger oxidation) reaction. The oxidative esterification of a number of derivatives of progesterone to produce the corresponding 17α-hydroxysteroid 17-acetate ester, such as testosterone acetate, is shown in Reaction (1). The oxidative lactonization of a number of derivatives of androstenedione to produce the 13,17-secoandrosteno-17,13α-lactone, such as testololactone, is shown in Reaction (2). The oxidative cleavage of the 17β-side-chain of 17α-hydroxyprogesterone to produce androstenedione and acetate is shown in Reaction (3). Reaction (1) is also catalysed by EC 1.14.99.4 (progesterone monooxygenase), and Reactions (2) and (3) correspond to that catalysed by EC 1.14.99.12 (androst-4-ene-3,17-dione monooxygenase). The possibility that a single enzyme is responsible for the reactions ascribed to EC 1.14.99.4 and EC 1.14.99.12 in other tissues cannot be excluded.

created 1999