PathwayStep1957 PathwayStep1959 PathwayStep1958 Arachidonic acid is hydroxylated to 20-HETE by CYP(3) Arachidonic acid is hydroxylated to 16/17/18-HETE by CYP(1) Arachidonic acid is hydroxylated to 19-HETE by CYP(2) Synthesis of (16-20)-hydroxyeicosatetraenoic acids (HETE) Authored: Williams, MG, 2012-02-24 Edited: Williams, MG, 2012-02-24 GENE ONTOLOGYGO:0097267 ISBN978-0-444-53219-0 Pubmed10681399 Pubmed19244215 Reactome Database ID Release 432142816 Reactome, http://www.reactome.org ReactomeREACT_150134 Reviewed: Rush, MG, 2012-11-10 Similar to the lipoxygenases, cytochrome P450 (CYP) enzymes catalyse the hydroxylation and epoxygenation of arachidonic acid. However, whereas lipoxygenases use an active non-heme iron to abstract hydrogen directly from arachidonic acid, CYPs contain a heme-iron active site that oxidizes its substrate by a different mechanism. They hydroxylate arachidonic acid between C-5 and C-15 to produce lipoxygenase-like hydroxyeicosatetraenoic acids (HETEs) and add a hydroxyl moiety to the sp3-hybridized omega-carbons to form a unique class of HETEs. The transfer of oxygen to the unstable arachidonic acid intermediate terminates the reaction by forming HETE or epoxy-eicosatrienoic acid (EETs), respectively (Capdevila et al. 2000, Buczynski et al. 2009, Vance & Vance 2008).