Monocyclic monoterpene ketone monooxygenase explained

Monocyclic monoterpene ketone monooxygenase
Ec Number:	1.14.13.105

Monocyclic monoterpene ketone monooxygenase (1-hydroxy-2-oxolimonene 1,2-monooxygenase, dihydrocarvone 1,2-monooxygenase, MMKMO) is an enzyme with systematic name (-)-menthone,NADPH:oxygen oxidoreductase.^{[1] [2] [3]} This enzyme catalyses the following chemical reaction

(1) (-)-menthone + NADPH + H⁺ + O₂

\rightleftharpoons (4R,7S)-7-isopropyl-4-methyloxepan-2-one + NADP⁺ + H₂O

(2) dihydrocarvone + NADPH + H⁺ + O²

\rightleftharpoons 4-isopropenyl-7-methyloxepan-2-one + NADP⁺ + H₂O

(3) (iso)-dihydrocarvone + NADPH + H⁺ + O₂

\rightleftharpoons 6-isopropenyl-3-methyloxepan-2-one + NADP⁺ + H₂O

(4a) 1-hydroxymenth-8-en-2-one + NADPH + H⁺ + O₂

\rightleftharpoons 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + NADP⁺ + H₂O

(4b) 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one

\rightleftharpoons 3-isopropenyl-6-oxoheptanoate (spontaneous)

Monocyclic monoterpene ketone monooxygenase is a flavoprotein (FAD).

Notes and References

1. van der Werf MJ, Swarts HJ, de Bont JA . Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene . Applied and Environmental Microbiology . 65 . 5 . 2092–102 . May 1999 . 10224006 . 91303 .
2. Van Der Werf MJ . Purification and characterization of a Baeyer-Villiger mono-oxygenase from Rhodococcus erythropolis DCL14 involved in three different monocyclic monoterpene degradation pathways . The Biochemical Journal . 347 Pt 3 . 693–701 . May 2000 . 10769172 . 1221005 . 10.1042/0264-6021:3470693 .
3. van der Werf MJ, Boot AM . Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14 . Microbiology . 146 (Pt 5) . 1129–41 . May 2000 . 10832640 . 10.1099/00221287-146-5-1129 . free .