Epoxygenases are a set of membrane-bound, heme-containing cytochrome P450 (CYP P450 or just CYP) enzymes that metabolize polyunsaturated fatty acids to epoxide products that have a range of biological activities.[1] The most thoroughly studied substrate of the CYP epoxylgenases is arachidonic acid. This polyunsaturated fatty acid is metabolized by cyclooxygenases to various prostaglandin, thromboxane, and prostacyclin metabolites in what has been termed the first pathway of eicosanoid production; it is also metabolized by various lipoxygenases to hydroxyeicosatetraenoic acids (e.g. 5-Hydroxyeicosatetraenoic acid, 12-Hydroxyeicosatetraenoic acid, 15-hydroxyicosatetraenoic acid) and leukotrienes (e.g. leukotriene B4, leukotriene C4) in what has been termed the second pathway of eicosanoid production. The metabolism of arachidonic acid to epoxyeicosatrienoic acids by the CYP epoxygenases has been termed the third pathway of eicosanoid metabolism.[2] Like the first two pathways of eicosanoid production, this third pathway acts as a signaling pathway wherein a set of enzymes (the epoxygenases) metabolize arachidonic acid to a set of products (the eicosatrienoic acid epoxides, abbreviated as EETs, which are classified as nonclassic eicosanoids) that act as secondary signals to work in activating their parent or nearby cells and thereby orchestrate functional responses. However, none of these three pathways is limited to metabolizing arachidonic acid to eicosanoids. Rather, they also metabolize other polyunsaturated fatty acids to products that are structurally analogous to the eicosanoids but often have different bioactivity profiles. This is particularly true for the CYP epoxygenases which in general act on a broader range of polyunsaturated fatty acids to form a broader range of metabolites than the first and second pathways of eicosanoid production. Furthermore, the latter pathways form metabolites many of which act on cells by binding with and thereby activating specific and well-characterized receptor proteins; no such receptors have been fully characterized for the epoxide metabolites. Finally, there are relatively few metabolite-forming lipoxygenases and cyclooxygenases in the first and second pathways and these oxygenase enzymes share similarity between humans and other mammalian animal models. The third pathway consists of a large number of metabolite-forming CYP epoxygenases and the human epoxygenases have important differences from those of animal models. Partly because of these differences, it has been difficult to define clear roles for the epoxygenase-epoxide pathways in human physiology and pathology.
^Cite error: The named reference Biochim Biophys Acta 2014 was invoked but never defined (see the help page).
^Cite error: The named reference Pharmacol Ther 2014 was invoked but never defined (see the help page).
Epoxygenases are a set of membrane-bound, heme-containing cytochrome P450 (CYP P450 or just CYP) enzymes that metabolize polyunsaturated fatty acids to...
metabolism of xenobiotics in the body. Cytochrome P4502C8 also possesses epoxygenase activity, i.e. it metabolizes long-chain polyunsaturated fatty acids...
metabolizes important endogenous compounds such as serotonin and, owing to its epoxygenase activity, various polyunsaturated fatty acids, converting these fatty...
acid (19-HETE) (see 20-hydroxyeicosatetraenoic acid) but also has epoxygenase activity in that it metabolizes docosahexaenoic acid to epoxides, primarily...
conditions. ALOXE3 preferentially metabolizes arachidonic acid to hepoxilins. Epoxygenases: these are cytochrome P450 enzymes which generate nonclassic eicosanoid...
their toxic forms (see table below for examples). CYP3A4 also possesses epoxygenase activity in that it metabolizes arachidonic acid to epoxyeicosatrienoic...
hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs) by epoxygenase. The production of these derivatives and their actions in the body are...
cytochrome P450 genes on chromosome no.10 arm q24. CYP2C19 also possesses epoxygenase activity: it is one of the principal enzymes responsible for attacking...
a specific subset of cytochrome P450 enzymes termed cytochrome P450 epoxygenases. These nonclassic eicosanoids are generally short-lived, being rapidly...
(19-HETE) (see 20-Hydroxyeicosatetraenoic acid). However, it also acts as an epoxygenase activity to metabolize docosahexaenoic acid to epoxides, primarily 19R...
humans (see epoxyeicosatrienoic acid, epoxydocosapentaenoic acid, and epoxygenase pages). Vernolic and coronaric acids are potentially toxic, causing multiple...
acid (19-HETE) (see 20-Hydroxyeicosatetraenoic acid) but also has epoxygenase activity in that it metabolizes docosahexaenoic acid to epoxides, primarily...
eicosapentaenoic acid (EPA), with certain cytochrome P450 epoxygenases. These epoxygenases can metabolize EPA to as many as 10 epoxides that differ in...
alkene,NADH:oxygen oxidoreductase. This enzyme is also called alkene epoxygenase. This enzyme participates in tetrachloroethene degradation. Small FJ...
9-oxo-octadecdienoic acid. Certain cytochrome P450 enzymes, the CYP epoxygenases, catalyze oxidation of LA to epoxide products viz., its 12,13-epoxide...
species through the metabolism of linoleic acid by cytochrome P450 (CYP) epoxygenase enzymes. These CYPs (CYP2C9 and probably other CYPs that metabolize polyunsaturated...
docosahexaenoic acid (DHA). Cell types that express certain cytochrome P450 (CYP) epoxygenases metabolize polyunsaturated fatty acids (PUFAs) by converting one of their...
polyunsaturated fatty acids that are made by various cytochrome P450 epoxygenases. EETs, EDPs, and EEQs have various effects in animals including vasodilation...
Gene ontology Molecular function iron ion binding arachidonic acid epoxygenase activity oxidoreductase activity, acting on paired donors, with incorporation...
activities. In addition to these monooxygenase actions, CYP458 possesses epoxygenase activity: it metabolizes the omega-3 fatty acids, docosahexaenoic acid...
primary tumor tissues of ovarian cancer. CYP2S1 has recently been assigned epoxygenase activity. It metabolizes 1) arachidonic acid to its various epoxides...
vernolic acid is made by the metabolism of linoleic acid by cytochrome P450 epoxygenase enzymes; under these circumstances it is termed leukotoxin because of...
human renal and liver microsome 20-HETE synthesis. CYP4A11 also has epoxygenase activity in that it metabolizes docosahexaenoic acid to epoxydocosapentaenoic...
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