IUBMB Enzyme Nomenclature


Accepted name: hepoxilin-epoxide hydrolase

Reaction: hepoxilin A3 + H2O = trioxilin A3

Glossary: hepoxilin A3 = (5Z,9E,14Z)-(8ξ,11R,12S)-11,12-epoxy-8-hydroxyicosa-5,9,14-trienoate
trioxilin A3 = (5Z,9E,14Z)-(8ξ,11ξ,12S)-8,11,12-trihydroxyicosa-5,9,14-trienoate

Other name(s): hepoxilin epoxide hydrolase; hepoxylin hydrolase; hepoxilin A3 hydrolase

Systematic name: (5Z,9E,14Z)-(8ξ,11R,12S)-11,12-epoxy-8-hydroxyicosa-5,9,14-trienoate hydrolase

Comments: Converts hepoxilin A3 into trioxilin A3. Highly specific for the substrate, having only slight activity with other epoxides such as leukotriene A4 and styrene oxide [2]. Hepoxilin A3 is an hydroxy-epoxide derivative of arachidonic acid that is formed via the 12-lipoxygenase pathway [2]. It is probable that this enzyme plays a modulatory role in inflammation, vascular physiology, systemic glucose metabolism and neurological function [4]. In vertebrates, five epoxide-hydrolase enzymes have been identified to date: EC (leukotriene-A4 hydrolase), EC (hepoxilin-epoxide hydrolase), EC (microsomal epoxide hydrolase), EC (soluble epoxide hydrolase) and EC (cholesterol 5,6-oxide hydrolase) [3].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 122096-98-4


1. Pace-Asciak, C.R. Formation and metabolism of hepoxilin A3 by the rat brain. Biochem. Biophys. Res. Commun. 151 (1988) 493-498. [PMID: 3348791]

2. Pace-Asciak, C.R. and Lee, W.-S. Purification of hepoxilin epoxide hydrolase from rat liver. J. Biol. Chem. 264 (1989) 9310-9313. [PMID: 2722835]

3. Fretland, A.J. and Omiecinski, C.J. Epoxide hydrolases: biochemistry and molecular biology. Chem. Biol. Interact. 129 (2000) 41-59. [PMID: 11154734]

4. Newman, J.W., Morisseau, C. and Hammock, B.D. Epoxide hydrolases: their roles and interactions with lipid metabolism. Prog. Lipid Res. 44 (2005) 1-51. [PMID: 15748653]

[EC created 1992, modified 2006]

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