Superoxide dismutase: determination of activity by inhibition of photosensitized chemiluminescence of glycyltryptophan.
A technique for quantitative determination of superoxide dismutase (SOD) in biological material is described. The technique is based on the riboflavin-photosensitized oxidation of Gly-Trp, which is accompanied by chemiluminescence. Formation of the luminescent product is inhibited by SOD. The dependence of SOD activity on reciprocal intensity of chemiluminescence is linear. The concentration for 50% inhibition is 7.5 ng/ml, and the minimum reliably determined concentration is about 2 ng/ml. The reaction is not sensitive to high concentrations of cyanide, which allows the separate determination of Cu,Zn- and Mn-SOD in mixtures.
Lozovskaya
E L
EL
Emmanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow. efrem@online.ru
Vartanyan
L S
LS
D000818:Animals; D004151:Dipeptides / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007700:Kinetics; D008163:Luminescent Measurements; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000494:pharmacology*; D051381:Rats; D012256:Riboflavin / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism*
D004151:Dipeptides; D017319:Photosensitizing Agents; C032120:glycyltryptophan; D013482:Superoxide Dismutase; D012256:Riboflavin