STUDIES ON THE MOBILIZATION OF IRON FROM FERRITIN BY ISOLATED RAT-LIVER MITOCHONDRIA

Rat liver mitochondria and rat liver mitoplasts mobilize iron from ferritin by a mechanism which depends on a respiratory substrate (preferentially succinate), a small molecular weight electron mediator (FMN, phenazine methosulphate or methylene blue) and (near) anaerobic conditions. The release process under optimized conditions (approx. 50 μmol/l FMN, 1 mmol/l succinate, 0.35 mmol/l Fe(III) (as ferritin iron), 37°C and pH 7.40) amounts to 0.9-1.2 nmol iron/mg protein per min. The results suggest that ferritin might function as an intermediate in the cytosolic transport of iron to the mitochondria. © 1979.