Stimulated decay of Superoxide caused by ferritin-bound copper

• Published in: FEBS letters Vol. 328; no. 3; pp. 263 - 267
• Main Authors: Bolann, Bjørn J., Ulvik, Rune J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 16-08-1993; Elsevier
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Apoferritins - metabolism; Binding and carrier proteins; Biological and medical sciences; Catalysis; Copper; Copper - metabolism; Ferritin; Ferritins - metabolism; Fundamental and applied biological sciences. Psychology; Horses; Kinetics; Proteins; Superoxide; Superoxides - metabolism; Superoxide; Catalysis; Copper; Ferritin; Ferroprotein; Hyperoxides; Binding capacity
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(93)80940-V

The redox interaction between O
2
− and ferritin cannot solely be regarded as a Fe(II) release reaction. We demonstrate that native copper bound to horse spleen ferritin and apoferritin, stimulated the decay of O
2
− in a catalytic reaction. Copper was determined by atomic absorption spectrophotometry. Decay of O
2
− was monitored spectrophotometrically as the decrease in (
A
250-
A
360) at pH 9.5. The catalytic effect was linearly related to the copper content of the protein. Ferritin copper was less efficient than equimolar CuCl
2, and iron-poor ferritin was more efficient than iron-rich ferritin. The results support a direct antioxidant function of ferritin.