What is "monooxygenase"

n. (context enzyme English) Any oxygenase enzyme that catalyzes the incorporation of a single atom of molecular oxygen into a substrate, the other atom being reduced to water; active in the metabolism of many foreign compounds

Monooxygenases are enzymes that incorporate one hydroxyl group into substrates in many metabolic pathways. In this reaction, the two atoms of dioxygen are reduced to one hydroxyl group and one HO molecule by the concomitant oxidation of NAD(P)H. One important subset of the monooxygenases, the cytochrome P450 omega hydroxylases, is used by cells to metabolize arachidonic acid (i.e. eicosatetraenoic acid) to the cell signaling molecules, 20-hydroxyeicosatetraenoic acid or to reduce or totally inactivate the activate signaling molecules for example by hydoxylating leukotriene B4 to 20-hydroxy-leukotriene B5, 5-hydroxyeicosatetraenoic acid to 5,20-dihydroxyeicosatetraenoic acid, 5-oxo-eicosatetraenoic acid to 5-oxo-20-hydroxyeicosatetraenoic acid, 12-hydroxyeicosatetraenoic acid to 12,20-dihydroxyeicosatetraenoic acid, and epoxyeicosatrienoic acids to 20-hydroxy-epoxyeicosatrienoic acids.