Epoxide Hydrolase 4 (EPHX4)

EPHX4 belongs to the AB hydrolase superfamily.In contrast to other members of the AB hydrolase superfamily, lacks the conserved Ser residue at position 169, which is replaced by an Asp residue, suggesting it has no hydrolase activity. Epoxide hydrolase (also known as epoxide hydratase) functions in detoxication during drug metabolism. It converts epoxides to trans-dihydrodiols, which can be conjugated and excreted from the body. Epoxides result from the degradation of aromatic compounds.

Epoxides are significant as cytochrome P450 oxidase metabolites of unsaturated carbon-carbon bonds, but are also mutagenic. Epoxide hydrolase is present in large quantity on endoplasmic reticulum.