Details

Autor(en) / Beteiligte

• Bryngelson, Peter A
• Maroney, Michael J
• Sigel, Roland K. O
• Sigel, Helmut
• Sigel, Astrid

Titel

Nickel Superoxide Dismutase

Ist Teil von

• Nickel and Its Surprising Impact in Nature, 2007, p.417-443

Ort / Verlag

Chichester, UK: John Wiley & Sons, Ltd

Erscheinungsjahr

2007

Link zum Volltext

Quelle

Wiley Online Library All Obooks

Beschreibungen/Notizen

• Superoxide dismutases (SODs) protect cells from the deleterious effects of superoxide, or reactive oxygen species derived from superoxide. Many aquated metal ions, including Cu 2+ ,Mn 2+ , and Fe 2+ , are capable of SOD activity, but Ni 2+ is not among them. Because the Ni(III/II) couple lies at over +1 V and the Ni(II/I) couple is lower than −1 V in aqueous solution, Ni has only one common oxidation state in water, Ni(II). Nickel is therefore an unlikely metal center for a SOD. Nonetheless, NiSODs have been identified in a variety of microorganisms. The NiSODs have many similarities with the Mn/Fe and CuZnSODs, but form a distinct group based on the metal content and ligand environment of the nickel center, the protein structure, and several aspects of the reaction mechanism. This review covers aspects of the structure and function of NiSOD, and compares and contrasts the mechanism employed by this enzyme with the more common SODs. Although NiSOD takes advantage of many strategies found in other SODs, the use of a metal that lacks natural redox chemistry in water and the application of the protein to create an active site with the requisite redox chemistry that employs cysteine thiolate ligands, constitutes a completely novel approach to the elimination of superoxide in biological systems and thus contributes to the biodiversity of mechanisms for oxygen detoxification.