Epoxide Hydrolase 1, Microsomal (EPHX1)

Epoxide hydrolase is a critical biotransformation enzyme that converts epoxides from the degradation of aromatic compounds to trans-dihydrodiols which can be conjugated and excreted from the body. The deduced amino acid sequence of the human enzyme was found to be 80% similar to the previously reported rabbit enzyme and 84% similar to the deduced rat protein sequence. The N-terminal amino acids deduced from the human cDNA were identical to the published 19 N-terminal amino acids of the purified human enzyme. Northern blot analysis showed a single mRNA band of 1.8 kilobases. Southern blot analysis indicated that there is only 1 copy of the gene per haploid genome. Several restriction fragment length polymorphisms were observed with the human EPOX cDNA.