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?3.4.11.6, aminopeptidase B). It also converts leukotriene A4?into leukotriene B4, unlike EC?3.2.2.10, soluble epoxide hydrolase, which converts leukotriene A4?into 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid [3,4]. In vertebrates, five epoxide-hydrolase enzymes have been identified to date: EC?3.3.2.6?(leukotriene-A4?hydrolase), EC?3.3.2.7?(hepoxilin-epoxide hydrolase), EC?3.3.2.9?(microsomal epoxide hydrolase), EC?3.3.2.10?(soluble epoxide hydrolase) and EC?3.3.2.11?(cholesterol-5,6-oxide hydrolase) [3].
