Chemiluminescence of lipid vesicles supplemented with cytochrome c and hydroperoxide.
The increase in light emission of hydroperoxide-supplemented cytochrome c observed on addition of lipid vesicles was related to the degree of unsaturation of the fatty acids of the phospholipids: dipalmitoyl phosphatidylcholine was without effect, whereas dioleoyl phosphatidylcholine and soya-bean phosphatidylcholine enhanced chemiluminescence 2- and 3-fold respectively. Effects on light-emission were similar to those on O2 uptake. The chemiluminescence of the present system was sensitive to cyanide and to the radical trap 2,5-di-t-butylquinol, indicating a catlytic activity of cytochrome c and the presence of free-radical species respectively. Lipid-vesicle enhanced chemiluminescence showed different kinetic behaviours, apparently depending on unsaturation: three phases are described for soya-bean phosphatidylcholine, whereas only one phase was present in mixtures containing dipalmitoyl and dioleoyl phospholipids. Chemiluminescence of lipid vesicles supplemented with cytochrome c and hydroperoxide showed similar kinetic patterns with H2O2 and primary (ethyl) and tertiary (t-butyl and cumene) hydroperoxides. Participation of singlet molecular oxygen, mainly on the phase III of chemiluminescence, is suggested by the increase of light-emission by 1,4-diazabicyclo[2.2.2]-octane as well as by data from spectral analysis.
D003486:Cyanides / Q000494:pharmacology; D003574:Cytochrome c Group; D006873:Hydroquinones / Q000494:pharmacology; D007700:Kinetics; D008081:Liposomes; D008163:Luminescent Measurements; D008954:Models, Biological; D010100:Oxygen; D010545:Peroxides
D003486:Cyanides; D003574:Cytochrome c Group; D006873:Hydroquinones; D008081:Liposomes; D010545:Peroxides; C019359:2,5-di-tert-butylhydroquinone; D010100:Oxygen