Three recombinant human apoferritin variants were added to ferrous iron and the amount of lipid peroxidation produced by hydrogen peroxide was studied. The H-apoferritin had the strongest inhibitory effect on lipid peroxidation, probably due to its ferroxidase activity. The L-apoferritin inhibited lipid peroxidation slowly and only at neutral pH. The H-mutant 91, deleted of the last 22 C-terminal amino acids, and which is not able to form an iron core, had minimal effects on iron lipid peroxidation. It was concluded that both ferro-oxidase and iron mineralization activities are necessary for ferritin iron detoxifying action.
