Chelation of Iron and Zinc by Protoporphyrin Catalyzed by Mitochondrial Preparations

Abstract

Sonication, freezing and thawing, treatment of mitochondria with Tween‐Span surfactants and other procedures applied to isolate ferrochelatase from the liver mitochondria showed that the most active in releasing the enzyme was the combined action of Tween 20 at a final concentration of 15 mg/ml and sonic irradiation on the mitochondrial suspensions, previously subjected to freezing and thawing. A 20–40 fold purification of the enzyme was achieved by ammonium sulphate fractionation and chromatography on dextran gels of “solubilized” ferrochelatase. Variations of the yield of the release of ferrochelatase from the mitochondria suggest that the localization of the enzyme within the mitochondrial structure is heterogeneous.