Description_x000D_ General description_x000D_ A shell of 24 protein subunits (apoferritin) and a core Fe 3+ ions with a peptide MW of 440 kDa. Review of the ferritin-like superfamily of iron-storage proteins, virtually ubiquitous in life on earth._x000D_ Application_x000D_ Ferritin from equine spleen has been used:_x000D_ • in mycobacterial growth assay_x000D_ • in size-exclusion chromatography_x000D_ • in labeling of macrophage cells_x000D_ • as a reference standard in muon spin spectroscopy_x000D_ Biochem/physiol Actions_x000D_ A ubiquitous iron storage protein that plays a key role in iron metabolism. It serves as an intracellular iron reserve (particularly in spleen, liver, intestinal mucosa, and bone marrow) and functions in iron detoxification. Studies have shown that ferritin iron incorporation is mediated by a ferroxidase activity associated with ferritin H subunits and a nucleation center associated with ferritin L subunits. Release of iron from ferritin has an essential role in iron-dependent lipid peroxidation and may contribute to free radical-induced cell damage in vivo. Therefore, by binding iron, ferritin may function as an antioxidant.