Dismutase

With few exceptions superoxide dismutases isolated from prokaryotes and from mitochondria contain manganese or iron (Lindmark and Muller, 

1974 Puget and Michelson, 1974a,b), whereas those from the cytosol of eukaryotes contain copper and zinc (Fridovich, 1974). 

Iron-containing superoxide dismutases have been isolated from a variety of microbial sources (Yost and Fridovich, 1973 Asada et al, 1975 Lumsden and Hall, 1974 Puget and Michelson, 1974a,b Yamakura, 1976). The crystallization and preliminary crystal data of an iron-containing superoxide dismutase from Pseudomonas ovalis has been reported (Yamakura et al, 1976). 

Combined ESR and optical titrations with azide point to the presence of two binding sites on iron (III), with only the first being occupied at room temperature and the second azide binding as a result of freezing the aqueous solution (Slykhouse and Fee, 1976). The results suggest that each of the two iron (III) atoms of the super oxide dismutase has two coordination positions available for the interaction with solute species, but only one is necessary for catalysis of the superoxide dismutation reaction. 

The ESR spectra of the iron (III) super oxide dismutases appear to arise from a somewhat unusual ligand field. Results obtained from proton relaxation measurements of iron (III) superoxide dismutase suggests that water molecules and, presumably, solute molecules such as CN and O2 experience some difficulty in entering the first coordination sphere of the ferric ion (Villafranca et a/., 1974 Villafranca, 1976), whereas the ESR measurements indicate that O2 may have direct access to the iron (III). 

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Klapper, I., Hagstrom, R., Fine, R., Sharp, K., Honig, B. Focusing of electric fields in the active site of cu,zn superoxide dismutase. Proteins Struct. Pune. Genet. 1 (1986) 47-79. 

Klapper 1, R Hagstrom, RFine, K Sharp and B Honig 1986. Focusing of Electric Fields in tire Actir e Sit of CuZn Superoxide Dismutase Effects of Ionic Strength and Amino-Acid Substitution. Proteins Structure, Function and Genetics 1 47-59. 

Super milling dyes Supermumetal Supernovas Superoxide dismutase... 

Erythrocuprein, which contains about 60 wt % of the erythrocyte copper, hepatocuprein, and cerebrocuprein act as superoxide dismutases. Each contains two atoms of copper per molecule, having mol wt ca 34,000. The superoxide ion, O", and peroxide, two main toxic by-products of... 

Copper is one of the twenty-seven elements known to be essential to humans (69—72) (see Mineral nutrients). The daily recommended requirement for humans is 2.5—5.0 mg (73). Copper is probably second only to iron as an oxidation catalyst and oxygen carrier in humans (74). It is present in many proteins, such as hemocyanin [9013-32-3] galactose oxidase [9028-79-9] ceruloplasmin [9031 -37-2] dopamine -hydroxylase, monoamine oxidase [9001-66-5] superoxide dismutase [9054-89-17, and phenolase (75,76). Copper aids in photosynthesis and other oxidative processes in plants. 

Superoxide dismutase has been approved by the FDA for preventing reperfusion injury or damage to donor organ tissue (178). This enzyme is prepared by recombinant DNA technology and marketed by Bristol-Myers and Pharmacia-Chiron. 

Two classes of antioxidants are known the low-molecular weight compounds (tocopherols, ascorbate, -carotene, glutathione, uric acid and etc.) and the proteins (albumin, transferrin, caeruloplasmin, ferritin, etc.) including antioxidant enzymes (e.g. superoxide dismutase, catalase, glutathione peroxidase). 

Copper-zinc-superoxide dismutase (from blood cell haemolysis) [9054-89-1J Mr 32,000... 

CL Eisher, J-L Chen, J Li, D Bashford, L Noodleman. Density-functional and electrostatic calculations for a model of a manganese superoxide dismutase active site in aqueous solution. J Phys Chem 100 13498-13505, 1996. 

J Shen, CF Wong, S Subramaniam, TA Albright, JA McCammon. Partial electrostatic charges for the active center of Cu,Zn superoxide dismutase. J Comput Chem 11 346-350, 1990. 

Figure S.l The enzyme superoxide dismutase (SOD). SOD is a P structure comprising eight antiparallel P strands (a). In addition, SOD has two metal atoms, Cu and Zn (yellow circles), that participate in the catalytic action conversion of a superoxide radical to hydrogen peroxide and oxygen. The eight p strands are arranged around the surface of a barrel, which is viewed along the barrel axis in (b) and perpendicular to this axis in (c). [(a) Adapted from J.S. Richardson. The stmcture of SOD was determined in the laboratory of J.S. and D.R. Richardson, Duke University.)...

McLachlan, A.D. Repeated folding pattern in copper-zinc superoxide dismutase. Nature 285 267-268, 1980. 

Richardson, J.S., et al. Similarity of three-dimensional stmcture between the immunoglobulin domain and the copper, zinc superoxide dismutase subunit. 

Tainer, J.A., et al. Determination and analysis of the 2 A structure of copper, zinc superoxide dismutase. 

When H2O2 is a necessary component of a luminescence system, it can be removed by catalase. If a luminescence system involves superoxide anion, the light emission can be quenched by destroying O2 with superoxide dismutase (SOD). The ATP cofactor usually present in the fresh extracts of the fireflies and the millipede Luminodesmus can be used up by their spontaneous luminescence reactions, eventually resulting in dark (nonluminous) extracts containing a luciferase or photoprotein. The process is, however, accompanied by a corresponding loss in the amount of luciferin or photoprotein. The use of ATPase and the elimination of Mg2+ in the extract may prevent such a loss. 

McCord, J. M., and Fridovich, I. (1969). Superoxide dismutase an enzymic function for erythrocuprein (hemocuprein)./. Biol. Chem. 244 6049-6055. 

Nakano, M. (1990). Assay for superoxide dismutase based on chemiluminescence of luciferin analog. Method. Enzymol. 186 227-232. 

Shimomura, O. (1992). The role of superoxide dismutase in regulating the light emission of luminescent fungi. J. Exp. Botany 43 1519-1525. 

Suzuki, N., etal. (1991). Reaction rates for the chemiluminescence of Cypridina luciferin analogs with superoxide a quenching experiment with superoxide dismutase. Agric. Biol. Chem. 55 157-160. 

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