Proteins of Iron Storage and Transport

Abstract

Publisher Summary This chapter presents the proteins of iron storage and transport and discusses their respective roles in iron metabolism within multicellular organisms. The relation of iron transport and storage proteins to intracellular iron metabolism and the clinical implications are also examined. The solution chemistry of iron and its role in biological systems are also discussed. In both prokaryotes and multicellular organisms, iron is stored in an intracellular form in which the iron is soluble, nontoxic, and available for release as and when required by the cell. The example of this form of iron is the iron-storage protein ferritin and, in mammals at least, its related lysosomal degradation product, hemosiderin. Both iron-storage components consist of a central inorganic ferric oxyhydroxide core, which, in ferritin, is surrounded by a well-organized protein shell, apoferritin. In the case of hemosiderin, the protein component is poorly characterized, but appears to contain some apoferritin, or degradation products thereof. The transferrins are a class of iron-binding proteins found in the physiological fluids of vertebrates. Siderophilin, the iron-binding protein of human serum also has antibacterial properties that are abolished by the addition of iron.