Epoxide hydrase, hepatic

Jerina, D. M., Dansette, P. M., Lu, A. Y. H., and Levin, W. Hepatic microsomal epoxide hydrase a sensitive radiometric assay for hydration of arene oxides of carcinogenic aromatic hydrocarbons. Mol. Pharmacol. (1977) 13 342-351. 

Figure 1. Epoxide hydrase and GSHt activities of trout hepatic microsomes and...

P. M. Dansette, V. B. Makedonska, D. M. Jerina, Mechanism of Catalysis for the Hydration of Substituted Styrene Oxides by Hepatic Epoxide Hydrase , Arch. Biochem. Biophys. 1978, 187, 290 - 298. 

Parkki MG. 1981. Inhibition of rat hepatic microsomal epoxide hydrase by heavy- and organometals in vitro. Adv Exp Med Biol 136 729-738. Part A. 

Table VII. Hepatic Epoxide Hydrase and Glutathione Transferase in Normal and Ascorbate Deficient Guinea Pigs...

Efforts to solubilize and isolate the P-450 monoxygenases from the microsomal membranes have been hampered by the facile conversion to a catalytically inactive form, cytochrome P-420. In 1968, however, a successful solubilization of catalytically active P-450 from hepatic microsomes was reported.30, 31 he solubilized system, which effected w-hydroxylation of fatty acids, required three coiq>onents for catalytic activity cytochrome P-450, NADPH-cytochrome c reductase, and a heat-stable, chloroform-soluble factor, the active component of which was identified as the microsomal lipid phosphatidylcholine.32 Further studies with this solubilized and reconstituted system have Indicated that the cytochrome P-450 and P-448 fractions have different catalytic activities 33-35 and that the terminal oxidase activity resides in the b-type cytochrome (P-450 or P-448) fraction rather than the cytochrome c reductase or lipid fractions.33, 36, 37 xhe cytochrome P-450 and P-448 were found to coiq>ete for reductase when present together.38 Cytochrome bs did not appear to be an obligatory component of the reconstituted systera.39 Cytochrome P-450 and P-448 fractions from rat liver were found to contain high levels of an epoxide hydrase, which can convert intermediate oxides to vicinal diols. Further purification has afforded fractions relatively free of cross-contamination of monoxygenase and hydrase enzymes. Recently, differential solubilization of monoxygenase activity towards a Type I substrate (naphthalene) and a Type II substrate (aniline) was... 

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