Mechanism for the generation of superoxide anion and singlet oxygen during heme compound-catalyzed linoleic acid hydroperoxide decomposition.
Heme compound, hematin or cytochrome c, catalyzes the decomposition of 13-hydroperoxy linoleic acid yielding both O2- and 1O2 under aerobic conditions. No 1O2 is produced when hydrogen peroxide and cumene hydroperoxide are used as substrates. In these experiments, both O2- and 1O2 could be precisely detected by a chemiluminescence method using a cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one, as a chemiluminescence probe, in the absence and presence of Cu-Zn superoxide dismutase in catalytic amounts. The reduction and oxidation cycle of ferric heme compound and the bimolecular reaction of peroxyl radicals are plausible reaction mechanisms for O2- and 1O2 production, respectively, in the systems studied.
Koga
S
S
College of Medical Care and Technology, Gunma University, Japan.
Nakano
M
M
Uehara
K
K
D002384:Catalysis; D006418:Heme / Q000378:metabolism*; D007093:Imidazoles; D066298:In Vitro Techniques; D008041:Linoleic Acids / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008163:Luminescent Measurements; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D011719:Pyrazines; D026082:Singlet Oxygen; D013481:Superoxides / Q000378:metabolism*
D007093:Imidazoles; D008041:Linoleic Acids; D008054:Lipid Peroxides; D011719:Pyrazines; D013481:Superoxides; C063412:2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo(1,2-alpha)pyrazin-3-one; D026082:Singlet Oxygen; C008285:linoleic acid hydroperoxide; D006418:Heme; D010100:Oxygen