Enantioselectivity of the hydrolysis of linoleic acid monoepoxides catalyzed by soybean fatty acid epoxide hydrolase.
Soybean epoxide hydrolase efficiently catalyzes the hydration of the two positional isomers of linoleic acid monoepoxides into their corresponding vic-diols. Kinetic analysis of the progress curves, obtained at low substrate concentrations (i.e. [So] much less than Km), and analysis of the residual substrates by chiral-phase HPLC, indicate that the hydrolase is highly enantioselective, i.e. cis-9R,10S-epoxy-12(Z)-octadecenoic and cis-12R,13S-epoxy-9(Z)-octadecenoic acids are preferentially hydrolyzed (the enantioselectivity ratios are 15 and 28, respectively). Importantly, these two enantiomers are the one formed preponderantly by epoxidation of linoleic acid by peroxygenase, a hydroperoxide-dependent oxidase we have previously described in soybean (Blée, E., and Schuber, F., Biochem. Biophys. Res. Commun. (1990) 173, 1354-1360).
Blee
E
E
Institut de Biologie Moléculaire des Plantes (CNRS UPR-406), DECM, Strasbourg, France.
Schuber
F
F
D002851:Chromatography, High Pressure Liquid; D004851:Epoxide Hydrolases / Q000378:metabolism*; D004852:Epoxy Compounds / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000737:chemistry / Q000378:metabolism*; D013025:Glycine max / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity
D004852:Epoxy Compounds; D008041:Linoleic Acids; D019787:Linoleic Acid; D004851:Epoxide Hydrolases