FeSOD dismutase

Superoxide dismutase (SOD, EC 1.15.1.1) is a scavenger of the superoxide anion, and therefore, provides protection against oxidative stress in biological systems [259]. Most SODs are homodimeric metalloenzymes and contain redox active Fe, Ni, Mn or Cu. The superoxide dismutation by SOD is among the fastest enzyme reactions known. The rate constant for CuZnSOD is = 2x 10 s [260], FeSOD is about one order of... 

These are (1) the copper-zinc superoxide dismutases, CuZnSOD, °° ° found in almost all eukaryotic cells and a very few prokaryotes, and (2) the manganese and iron superoxide dismutases, MnSOD and FeSOD, the former found in the mitochondria of eukaryotic cells, and both found in many prokaryotes. Recent studies of bacterial and yeast mutants that were engineered to contain no superoxide dismutases demonstrated that the cells were unusually sensitive... 

Superoxide dismutase (SOD) is a widely distributed enzyme that exists in a variety of forms. The copper-zinc enzyme (Cu,ZnSOD) is primarily located in the cytosol of eukaryotic cells. Mitochondria contain, in the matrix space, a distinctive cyanide-insensitive manganese-containing enzyme (MnSOD) similar to that found in prokaryotes. In addition, a ferrienzyme (FeSOD) has been identified in bacteria that is also insensitive to cyanide. Amino acid sequence homologies indicate two families of superoxide dismutases. One of these is composed of the Cu,ZnSODs and the other of MnSODs and FeSODs. All these superoxide dismutases catalyze the same reaction (2H -H O2 -h OJ H2O2 -t- O2) and with comparable efficiency. 

To diminish these threats, nature has created a family of metalloenzymes, the SODs. They catalyze the dismutation of superoxide to dioxygen and hydrogen peroxide (Eqs. (1) and (2)). They are differentiated by the redox-active metal copper (Cu/Zn SOD), manganese (MnSOD), iron (FeSOD), or nickel (NiSOD) superoxide dismutases and fall into three evolutionary families (Fig. 2) (10). The iron and manganese SODs are structurally similar and are found in prokaryotes and in the matrix of mitochondria (near the electron transport chain), respectively. Nickel containing SODs are known in some prokaryotes, whereas Cu/Zn are present in the cytosols of virtually all eukaryotic cells and have an independent evolutionary history. 

Superoxide dismutase (SOD), catalases, and peroxidases inhibit oxidation in vivo by inactivating ROS. There are multiple forms of SOD and all contain metal ions, which are integral to die dismutation reaction. For FeSOD, the dismutation is attributed to the following reactions. 

---