
Cytochrome P450 omega hydroxylase

Cytochrome P450 omega hydroxylases, also termed cytochrome P450 ω-hydroxylases, CYP450 omega hydroxylases, CYP450 ω-hydroxylases, CYP omega hydroxylase, CYP ω-hydroxylases, fatty acid omega hydroxylases, cytochrome P450 monooxygenases, and fatty acid monooxygenases, are a set of cytochrome P450-containing enzymes that catalyze the addition of a hydroxyl residue to a fatty acid substrate. The CYP omega hydroxylases are often referred to as monoxygenases; however, the monooxygenases are CYP450 enzymes that add a hydroxyl group to a wide range of xenobiotic (e.g. drugs, industrial toxins) and naturally occurring endobiotic (e.g. cholesterol) substrates, most of which are not fatty acids. The CYP450 omega hydroxylases are accordingly better viewed as a subset of monooxygenases that have the ability to hydroxylate fatty acids. While once regarded as functioning mainly in the catabolism of dietary fatty acids, the omega oxygenases are now considered critical in the production or break-down of fatty acid-derived mediators which are made by cells and act within their cells of origin as autocrine signaling agents or on nearby cells as paracrine signaling agents to regulate various functions such as blood pressure control and inflammation.
Action.
The omega oxygenases metabolize fatty acids (RH) by adding a hydroxyl (OH) to their terminal (i.e. furthest from the fatty acids' carboxy residue) carbons; in the reaction, the two atoms of molecular oxygen(O2[ are reduced to one hydroxyl group and one water (H2O molecule) by the concomitant oxidation of NAD(P)H (see monooxygenase).
RH + O2 + NADPH + H+ → ROH + H2O + NADP+
Functions.
CYP450 enzymes belong to a superfamily which in humans is composed of at least 57 CYPs; within this superfamily, members of six CYP4A subfamilies, (which are CYP4A, CYP4B, CYP4F, CYP4V, CYP4X, and CYP4z) possess ω-hydroxylase activity viz., CYP4A, CYP4B, and CYP4F CYP2U1 also possesses ω hydroxylase activity. These CYP ω-hydroxylases can be categorized into several groups based on their substrates and consequential function