IUBMB Enzyme Nomenclature


Accepted name: leukotriene-A4 hydrolase

Reaction: leukotriene A4 + H2O = leukotriene B4

Glossary: leukotriene A4 = (7E,9E,11Z,14Z)-(5S,6S)-5,6-epoxyicosa-7,9,11,14-tetraenoate
leukotriene B4 = (6Z,8E,10E,14Z)-(5S,12R)-5,12-dihydroxyicosa-6,8,10,14-tetraenoate

Other name(s): LTA4 hydrolase; LTA4H; leukotriene A4 hydrolase

Systematic name: (7E,9E,11Z,14Z)-(5S,6S)-5,6-epoxyicosa-7,9,11,14-tetraenoate hydrolase

Comments: This is a bifunctional zinc metalloprotease that displays both epoxide hydrolase and aminopeptidase activities [4,6]. It preferentially cleaves tripeptides at an arginyl bond, with dipeptides and tetrapeptides being poorer substrates [6] (see EC, aminopeptidase B). It also converts leukotriene A4 into leukotriene B4, unlike EC, soluble epoxide hydrolase, which converts leukotriene A4 into 5,6-dihydroxy-7,9,11,14-icosatetraenoic acid [3,4]. 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) [5].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 90119-07-6


1. Evans, J.F., Dupuis, P. and Ford-Hutchinson, A.W. Purification and characterisation of leukotriene A4 hydrolase from rat neutrophils. Biochim. Biophys. Acta 840 (1985) 43-50. [PMID: 3995081]

2. Minami, M., Ohno, S., Kawasaki, H., Raadmark, O., Samuelsson, B., Jörnvall, H., Shimizu, T., Seyama, Y. and Suzuki, K. Molecular cloning of a cDNA coding for human leukotriene A4 hydrolase - complete primary structure of an enzyme involved in eicosanoid synthesis. J. Biol. Chem. 262 (1987) 13873-13876. [PMID: 3654641]

3. Haeggström, J., Meijer, J. and Radmark, O. Leukotriene A4. Enzymatic conversion into 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid by mouse liver cytosolic epoxide hydrolase. J. Biol. Chem. 261 (1986) 6332-6337. [PMID: 3009453]

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]

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

6. Orning, L., Gierse, J.K. and Fitzpatrick, F.A. The bifunctional enzyme leukotriene-A4 hydrolase is an arginine aminopeptidase of high efficiency and specificity. J. Biol. Chem. 269 (1994) 11269-11267. [PMID: 8157657]

7. Ohishi, N., Izumi, T., Minami, M., Kitamura, S., Seyama, Y., Ohkawa, S., Terao, S., Yotsumoto, H., Takaku, F. and Shimizu, T. Leukotriene A4 hydrolase in the human lung. Inactivation of the enzyme with leukotriene A4 isomers. J. Biol. Chem. 262 (1987) 10200-10205. [PMID: 3038871]

[EC created 1989, modified 2006]

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