title: Inactivation of potato lipoxygenase by hydroperoxy acids as suicide substrates.
abstract: The preincubation of potato lipoxygenase with 9(S)-hydroperoxyoctadecatrienoic acid, 15(S)-hydroperoxyeicosatetraenoic acid or 5(S)-hydroperoxyeicosatetraenoic acid which can be subjected to further lipoxygenation led to the gradual inactivation of the lipoxygenase activity, whereas 13(S)-hydroperoxy-9,13,15-octadecatrienoic acid or 15(S)-hydroperoxy-11,13,17-eicosatrienoic acid had no significant effect. The inhibitory effect of the peroxy acids was abolished by hemoglobin. Based on these observations, it is proposed that the unstable epoxide intermediates from the respective peroxy acids may be responsible for the inactivation of potato lipoxygenase. In the comparative study, it was found that 15(S)-hydroperoxyeicosatetraenoic acid possessed more effective inhibitory role than the other acids with Ki value of 250 microM.
authors.affiliation: Chungnam National University, Department of Food & Nutrition, Daejeon, Korea.
authors.forename: M R
authors.initials: MR
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: D E
authors.initials: DE
authors.lastname: Sok
mesh_terms: D007536:Isomerism; D007700:Kinetics; D015289:Leukotrienes / Q000494:pharmacology; D008042:Linolenic Acids / Q000494:pharmacology; D008054:Lipid Peroxides / Q000494:pharmacology; D016859:Lipoxygenase Inhibitors; D010944:Plants / Q000201:enzymology*; D011198:Solanum tuberosum / Q000201:enzymology; D013329:Structure-Activity Relationship
chemical_list: D015289:Leukotrienes; D008042:Linolenic Acids; D008054:Lipid Peroxides; D016859:Lipoxygenase Inhibitors; C060746:9-hydroperoxy-10,12,15-octadecatrienoic acid; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid