Sequence similarity of mammalian epoxide hydrolases to the bacterial haloalkane dehalogenase and other related proteins

Arand, Michael; Grant, David F.; Beetham, Jeffrey K.; Friedberg, Thomas; Oesch, Franz; Hammock, Bruce D.

doi:10.1016/0014-5793(94)80278-5

Cited by 144 publications

(138 citation statements)

References 30 publications

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“…This enzyme, which represents a single known and highly conserved gene product with over 90% homology between rodent and human (30), can be inhibited selectively and competitively in vitro by a variety of urea, carbamate, and amide derivatives (16,18). We have shown that injection of one such inhibitor, DCU, into spontaneously hypertensive rats resulted in a lowering of blood pressure.…”

Section: Discussionmentioning

confidence: 99%

Inhibitors of soluble epoxide hydrolase attenuate vascular smooth muscle cell proliferation

Davis

Thompson

Howard

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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Atherosclerosis, in its myriad incarnations the foremost killer disease in the industrialized world, is characterized by aberrant proliferation of vascular smooth muscle (VSM) cells in part as a result of the recruitment of inflammatory cells to the blood vessel wall. The epoxyeicosatrienoic acids are synthesized from arachidonic acid in a reaction catalyzed by the cytochrome P450 system and are vasoactive substances. Metabolism of these compounds by epoxide hydrolases results in the formation of compounds that affect the vasculature in a pleiotropic manner. As an outgrowth of our observations that urea inhibitors of the soluble epoxide hydrolase (sEH) reduce blood pressure in spontaneously hypertensive rats as well as the findings of other investigators that these compounds possess antiinflammatory actions, we have examined the effect of sEH inhibitors on VSM cell proliferation. We now show that the sEH inhibitor 1-cyclohexyl-3-dodecyl urea (CDU) inhibits human VSM cell proliferation in a dose-dependent manner and is associated with a decrease in the level of cyclin D1. In addition, cis-epoxyeicosatrienoic acid mimics the growth-suppressive activity of CDU; there is no evidence of cellular toxicity or apoptosis in CDU-treated cells when incubated with 20 μM CDU for up to 48 h. These results, in light of the antiinflammatory and antihypertensive properties of these compounds that have been demonstrated already, suggest that the urea class of sEH inhibitors may be useful for therapy for diseases such as hypertension and atherosclerosis characterized by exuberant VSM cell proliferation and vascular inflammation

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Section: Discussionmentioning

confidence: 99%

Inhibitors of soluble epoxide hydrolase attenuate vascular smooth muscle cell proliferation

Davis

Thompson

Howard

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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111

112

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“…This information has been forthcoming from numerous sequence comparisons, biochemical, and crystallographic investigations. Based on sequence alignment analyses, it was concluded that sEH belongs to a broad group of a/b hydrolase enzymes that include bacterial haloalkane dehalogenase [32,66]. The alignment characterization also lead to identification of a proposed catalytic triad of amino acids within sEH.…”

Section: Mechanism Of Action/enzymatic Mechanismmentioning

confidence: 99%

“…Like sEH, mEH is a member of the a/b-hydrolase enzyme family [66]. Based on its similarity with bacterial haloalkane dehalogenases and other epoxide hydrolases, a catalytic triad consisting of a His 431 , Asp 226 , and a Glu 404 has been proposed [129,130].…”

Section: Mechanism Of Action/enzymatic Mechanismmentioning

confidence: 99%

Epoxide hydrolases: biochemistry and molecular biology

Fretland

Omiecinski

2000

Chemico-Biological Interactions

273

185

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Epoxides are organic three-membered oxygen compounds that arise from oxidative metabolism of endogenous, as well as xenobiotic compounds via chemical and enzymatic oxidation processes, including the cytochrome P450 monooxygenase system. The resultant epoxides are typically unstable in aqueous environments and chemically reactive. Biol. Chem. 260 (1985) 1630-1640). Therefore, it is of vital importance for the biological organism to regulate levels of these reactive species. The epoxide hydrolases (E.C. 3.3.2.3) belong to a sub-category of a broad group of hydrolytic enzymes that include esterases, proteases, dehalogenases, and lipases Beetham et al. (DNA Cell Biol. 14 (1995) 61 -71). In particular, the epoxide hydrolases are a class of proteins that catalyze the hydration of chemically reactive epoxides to their corresponding dihydrodiol products. Simple epoxides are hydrated to their corresponding vicinal dihydrodiols, and arene oxides to trans-dihydrodiols. In general, this hydration leads to more stable and less reactive intermediates, however exceptions do exist. In mammalian species, there are at least five epoxide hydrolase forms, microsomal cholesterol 5,6-oxide hydrolase, hepoxilin A 3 hydrolase, leukotriene A 4 hydrolase, soluble, and microsomal epoxide hydrolase. Each of these enzymes is distinct chemically and immunologically. Table 1 illustrates some general properties for each of these classes of hydrolases. Fig. 1 provides an overview of selected model substrates for each class of epoxide hydrolase.

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“…The soluble epoxide hydrolase (sEH, EC 3.3.2.3) 1 is a member of the α/β-hydrolase fold family of enzymes [1] and catalyzes the hydrolysis of an epoxide to its corresponding diol through the catalytic addition of a water molecule [2]. The endogenous substrates for the sEH include epoxides of arachidonic acid [3,4] and linoleic acid [5,6].…”

Section: Introductionmentioning

confidence: 99%

Fluorescent substrates for soluble epoxide hydrolase and application to inhibition studies

Jones

Wolf

Morisseau

et al. 2005

Analytical Biochemistry

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Inhibition of the mammalian soluble epoxide hydrolase (sEH) is a promising new therapy in the treatment of disorders resulting from hypertension and vascular inflammation. A spectrophotometric assay (4-nitrophenyl-trans-2,3-epoxy-3-phenylpropyl carbonate, NEPC) is currently used to screen libraries of chemicals; however this assay lacks the required sensitivity to differentiate the most potent inhibitors. A series of fluorescent α-cyanoester and α-cyanocarbonate epoxides that produce a strong fluorescent signal on epoxide hydrolysis by both human and murine sEH were designed as potential substrates for an in vitro inhibition assay. The murine enzyme showed a broad range of specificities, whereas the human enzyme showed the highest specificity for cyano(6-methoxynaphthalen-2-yl)methyl trans- [(3-phenyloxiran-2-yl) methyl] carbonate. An in vitro inhibition assay was developed using this substrate and recombinant enzyme. The utility of the fluorescent assay was confirmed by determining the IC 50 values for a series of known inhibitors. The new IC 50 values were compared with those determined by spectrophotometric NEPC and radioactive tDPPO assays. The fluorescent assay ranked these inhibitors on the basis of IC 50 values, whereas the NEPC assay did not. The ranking of inhibitor potency generally agreed with that determined using the tDPPO assay. These results show that the fluorescence-based assay is a valuable tool in the development of sEH inhibitors by revealing structure-activity relationships that previously were seen only by using the costly and labor-intensive radioactive tDPPO assay. KeywordsSoluble epoxide hydrolase; α-Cyanoester; α-Cyanocarbonate; Kinetic assay; Fluorescent substrateThe soluble epoxide hydrolase (sEH, EC 3.3.2.3) 1 is a member of the α/β-hydrolase fold family of enzymes [1] and catalyzes the hydrolysis of an epoxide to its corresponding diol through the catalytic addition of a water molecule [2]. The endogenous substrates for the sEH include epoxides of arachidonic acid [3,4] and linoleic acid [5,6]. Arachidonic acid epoxides (epoxyeicosatrienoic acid epoxides, EETs) are known modulators of blood pressure [7,8] and vascular permeability [9,10]. It has been shown that sEH inhibition not only lowers blood * Corresponding author. Fax: +1 530 752 1537. E-mail address:bdhammock@ucdavis.edu (B.D. Hammock).. 1 Abbreviations used: sEH, soluble epoxide hydrolase; EET, epoxyeicosatrienoic acid epoxides; NEPC, 4-nitrophenyl-trans-2,3-epoxy-3-phenylpropyl carbonate; TEA, triethylamine; TLC, thin-layer chromatography; TMS, tetramethylsilane; ppm, parts per million; oa-TOF, orthogonal acceleration time-of-flight; THF, tetrahydrofuran; m-CPBA, m-chloroperbenzoic acid; BSA, bovine serum albumin; RFU, relative fluorescent units; OD, optical density; DMSO, dimethyl sulfoxide; EDCI, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; tDPPO, [ 3 H] pressure in rodent models but also offers protection against hypertension-related renal damage [4,11,12].For the past 6 years, we have investi...

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Sequence similarity of mammalian epoxide hydrolases to the bacterial haloalkane dehalogenase and other related proteins

Cited by 144 publications

References 30 publications

Inhibitors of soluble epoxide hydrolase attenuate vascular smooth muscle cell proliferation

Inhibitors of soluble epoxide hydrolase attenuate vascular smooth muscle cell proliferation

Epoxide hydrolases: biochemistry and molecular biology

Fluorescent substrates for soluble epoxide hydrolase and application to inhibition studies

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