Ferritin and superoxide-dependent lipid peroxidation.

摘要: Ferritin was found to promote the peroxidation of phospholipid liposomes, as evidenced by malondialdehyde formation, when incubated with xanthine oxidase, xanthine, and ADP. Activity inhibited superoxide dismutase but markedly stimulated addition catalase. Xanthine oxidase-dependent iron release from ferritin, measured spectrophotometrically using ferrous chelator 2,2'-dipyridyl, also dismutase, suggesting that can mediate reductive ferritin. Potassium in crown ether promoted dismutase-inhibitable Catalase had little effect on rate ferritin; thus hydrogen peroxide appears inhibit lipid preventing formation an initiating species rather than inhibiting EPR spin trapping 5,5-dimethyl-1-pyrroline-N-oxide used observe free radical production this system. Addition ferritin oxidase system resulted loss trap adduct interaction between The resultant spectrum a hydroxyl which abolished These data suggest may function vivo source for promotion superoxide-dependent peroxidation. Stimulation inhibition catalase suggests that, system, initiation is not via iron-catalyzed Haber-Weiss reaction.