Manganese Proteins with Mono‐ and Dinuclear Metal Sites

Abstract

Although manganese is not as widely recognized in bioinorganic chemistry as iron and copper, it nevertheless plays an essential role in several key biological processes. Consequently, manganese concentrations are tightly regulated in most cells. Several Mn‐specific transporters have been identified and a novel Mn‐regulatory protein has been characterized. Manganese‐activated enzymes are proteins that have relatively weak affinities for Mn; in many cases, these are isolated without any metal bound. Manganese‐activated enzymes are especially important in hydrolytic reactions and appear, in at least some cases, to have physiologically significant changes in activity that respond to changes in Mn concentration. The best‐characterized Mn proteins are redox‐active enzymes, where Mn typically cycles between the Mn(II) and Mn(III) oxidation states, although some Mn(IV)‐containing species are known.

Quantitative elemental imaging in eukaryotic algae

“…cytochrome c oxidase), and can directly be bound to amino acids in catalytic centers of enzymes 43 , 87 , 89–91 Mn is also essential and critically involved in several enzymes in DNA metabolism, detoxification of reactive oxygen species, and carbohydrate metabolism. 92–95 Fe, Cu, and Mn, in addition to their many important contributions to general metabolism, are also critically employed in photosynthetic electron transfer and chloroplast metabolism. 96 , 97 Ni is used in enzymes in a wide range of organisms, e.g.…”