Stimulated decay of superoxide caused by ferritin-bound copper.
The redox interaction between O2.- and ferritin cannot solely be regarded as as a Fe(II) release reaction. We demonstrate that native copper bound to horse spleen ferritin and apoferritin, stimulated the decay of O2.- in a catalytic reaction. Copper was determined by atomic absorption spectrophotometry. Decay of O2.- was monitored spectrophotometrically as the decrease in (A250-A360) at pH 9.5. The catalytic effect was linearly related to the copper content of the protein. Ferritin copper was less efficient than equimolar CuCl2, and iron-poor ferritin was more efficient than iron-rich ferritin. The results support a direct antioxidant function of ferritin.
Laboratory of Clinical Biochemistry, University of Bergen, Haukeland Hospital, Norway.
B J
BJ
Bolann
R J
RJ
Ulvik
D000818:Animals; D001052:Apoferritins / Q000378:metabolism; D002384:Catalysis; D003300:Copper / Q000378:metabolism*; D005293:Ferritins / Q000378:metabolism*; D006736:Horses; D007700:Kinetics; D013481:Superoxides / Q000378:metabolism*
D013481:Superoxides; D003300:Copper; D005293:Ferritins; D001052:Apoferritins