title: Cress and potato soluble epoxide hydrolases: purification, biochemical characterization, and comparison to mammalian enzymes.
abstract: Affinity chromatographic methods were developed for the one-step purification to homogeneity of recombinant soluble epoxide hydrolases (sEHs) from cress and potato. The enzymes are monomeric, with masses of 36 and 39 kDa and pI values of 4.5 and 5.0, respectively. In spite of a large difference in sequence, the two plant enzymes have properties of inhibition and substrate selectivity which differ only slightly from mammalian sEHs. Whereas mammalian sEHs are highly selective for trans- versus cis-substituted stilbene oxide and 1,3-diphenylpropene oxide (DPPO), plant sEHs exhibit far greater selectivity for trans- versus cis-stilbene oxide, but little to no selectivity for DPPO isomers. The isolation of a covalently linked plant sEH-substrate complex indicated that the plant and mammalian sEHs have a similar mechanism of action. We hypothesize an in vivo role for plant sEH in cutin biosynthesis, based on relatively high plant sEH activity on epoxystearate to form a cutin precursor, 9,10-dihydroxystearate. Plant sEHs display a high thermal stability relative to mammalian sEHs. This stability and their high enantioselectivity for a single substrate suggest that their potential as biocatalysts for the preparation of enantiopure epoxides should be evaluated.
authors.affiliation: Department of Entomology, University of California, Davis, California 95616, USA.
authors.forename: C
authors.initials: C
authors.lastname: Morisseau
authors.forename: J K
authors.initials: JK
authors.lastname: Beetham
authors.forename: F
authors.initials: F
authors.lastname: Pinot
authors.forename: S
authors.initials: S
authors.lastname: Debernard
authors.forename: J W
authors.initials: JW
authors.lastname: Newman
authors.forename: B D
authors.initials: BD
authors.lastname: Hammock
mesh_terms: D000818:Animals; D019607:Brassicaceae / Q000201:enzymology*; D002846:Chromatography, Affinity / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D004851:Epoxide Hydrolases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D007536:Isomerism; D008563:Membrane Lipids / Q000096:biosynthesis; D051379:Mice; D008956:Models, Chemical; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D011198:Solanum tuberosum / Q000201:enzymology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D013696:Temperature
chemical_list: C096857:1,3-diphenylpropene oxide; D004852:Epoxy Compounds; D008563:Membrane Lipids; D010940:Plant Proteins; D011994:Recombinant Proteins; C000521:cutin; D004851:Epoxide Hydrolases