Ferritins for chemistry and for life

Ferritins, highly symmetrical protein nanocages, are reactors for Fe2+ and dioxygen or hydrogen peroxide that are found in all kingdoms of life and in many different cells of multicellular organisms. They synthesize iron concentrates required for cells to make cofactors of iron proteins (heme. FeS, mono and diiron). The caged ferritin biominerals, Fe2O3 center dot H2O are also antioxidants, acting as sinks for iron and oxidants scavenged from damaged proteins; genetic regulation of ferritin biosynthesis is sensitive to both iron and oxidants. Here, the emphasis is ferritin oxidoreductase chemistry, ferritin ion channels for Fe2+ transit into and out of the protein cage and Fe3+O mineral nucleation, and uses of ferritin cages in nanocatalysis and nanomaterial synthesis. The ferritin nanocage as reactors for Fe2+ and oxygen, likely critical in the transition from anaerobic to aerobic life on earth, play central, contemporary roles that balance iron and oxygen chemistry in biology and have emerging roles in nanotechnology. (C) 2012 Elsevier B.V. All rights reserved.