Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. The protein is produced by almost all living organisms, including archaea, bacteria, algae, higher plants, and animals. It is the primary intracellular iron-storage protein in both prokaryotes and eukaryotes, keeping iron in a soluble and non-toxic form. In humans, it acts as a buffer against iron deficiency and iron overload. Ferritin is found in most tissues as a cytosolic protein, but small amounts are secreted into the serum where it functions as an iron carrier. Plasma ferritin is also an indirect marker of the total amount of iron stored in the body; hence, serum ferritin is used as a diagnostic test for iron-deficiency anemia. Aggregated ferritin transforms into a toxic form of iron called hemosiderin. Ferritin is a globular protein complex consisting of 24 protein subunits forming a hollow nanocage with multiple metal–protein interactions. Ferritin is a hollow globular protein of mass 474 kDa and comprising 24 subunits. Typically it has internal and external diameters of about 8 and 12 nm, respectively. Here you can see a recent cryoEM structure of the horse spleen ferritin (PDB code: 8I81)

#molecularart ... #immolecular ... #ferritin ... #transport ... #iron ... #horse ... #spleen ... #cryoem

Structure rendered with @proteinimaging and depicted with @corelphotopaint