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 17alpha-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-17,13alpha-lactone, such as testololactone, is shown in Reaction (2). The oxidative cleavage of the 17beta-side-chain of 17alpha-hydroxyprogesterone to produce androstenedione and acetate is shown in Reaction (3). Reaction (1) is also catalysed by EC 188.8.131.52 (progesterone monooxygenase), and Reactions (2) and (3) correspond to that catalysed by EC 184.108.40.206 (androst-4-ene-3,17-dione monooxygenase). The possibility that a single enzyme is responsible for the reactions ascribed to EC 220.127.116.11 and EC 18.104.22.168 in other tissues cannot be excluded.
EC 22.214.171.124 created 1999
Katagiri, M. and Itagaki, E.
A steroid ketone monooxygenase from Cylindrocarpon radicicola.
In: Muller, F. (Ed.), Chemistry and Biochemistry of Flavoenzymes, CRC Press, Florida, 1991, p. 102-108.