title: [Study of oxygen photoreduction in chloroplasts by the method of luminol and chlorophyll chemiluminescence].
abstract: The reduction of oxygen by irradiated chloroplasts was studied for elucidation of oxygen action site in the electron transport chain of photosynthesis. Chemiluminescence system, consisted of luminol and peroxidase, was used for registration of oxygen reduction products. In the first case chemiluminescence system was added to supernatant fraction after centrifugation of suspension of irradiated chloroplasts in order to determine H2O2 which was found to be the final product of oxygen photoreduction. In the second case when chloroplasts were illuminated in the presence of chemiluminescence system and oxygen the fact delayed luminescence of luminol was observed. This photoluminescence related also with the oxygen reduction in chloroplasts caused a possible formation of radicals HO2 (or -O2). The formation of this radicals and H2O2 was inhibited by DCMU, heating of chloroplasts at 45 degrees C for 5 min and by washing with EDTA and NH2OH. The rate of HO2 dissappearance was increased by methylviologen. The kinetics of photoluminescence of luminol and afterglow of chlorophyll in chloroplasts was identical in the interval from 20 msec to several seconds. It is suggested that oxygen reaction site is located near the reaction centre of chloroplasts.
mesh_terms: D002736:Chloroplasts / Q000378:metabolism*; D004579:Electron Transport; D005609:Free Radicals; D008163:Luminescent Measurements; D008165:Luminol / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism; D010545:Peroxides / Q000378:metabolism; D010788:Photosynthesis; D011724:Pyridazines / Q000378:metabolism*
chemical_list: D005609:Free Radicals; D010545:Peroxides; D011724:Pyridazines; D008165:Luminol; D010544:Peroxidases; D010100:Oxygen
vernacular_title: Izuchenie Fotovosstanobleniia Kisloroda khloroplastami Metodom Khemiliuminestsentsii Liuminola I Khlorofikla