title: Hydrogen peroxide: a potent activator of dioxygenase activity of soybean lipoxygenase.
abstract: Hydrogen peroxide, an ubiquitous biologically occurring peroxide, was found to stimulate the dioxygenase activity of soybean lipoxygenase at the physiologically attainable concentration. The increase in enzyme specific activity was directly proportional to hydrogen peroxide concentration up to 0.5 nM. A decrease in the stimulation of dioxygenase activity was observed at higher concentrations. At low enzyme concentration up to 28-fold stimulation was noted when the formation of lipid hydroperoxide was monitored spectrophotometrically. The stimulation was further confirmed by increased oxygen uptake. It is proposed that the mechanism for in vivo activation involves hydrogen peroxide.
authors.affiliation: Florida Toxicology Research Center, College of Public Health, University of South Florida, Tampa 33612.
authors.forename: A P
authors.initials: AP
authors.lastname: Kulkarni
authors.forename: A
authors.initials: A
authors.lastname: Mitra
authors.forename: J
authors.initials: J
authors.lastname: Chaudhuri
authors.forename: J Z
authors.initials: JZ
authors.lastname: Byczkowski
authors.forename: I
authors.initials: I
authors.lastname: Richards
mesh_terms: D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism / Q000494:pharmacology; D008084:Lipoxygenase / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D013025:Glycine max; D013056:Spectrophotometry, Ultraviolet
chemical_list: D008041:Linoleic Acids; D019787:Linoleic Acid; D006861:Hydrogen Peroxide; D010105:Oxygenases; D008084:Lipoxygenase