Superoxide dismutase , role

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

As described in Section 15.7, enzymes are the catalysts of biological reactions. Without enzymes, most of the reactions that occur in a cell would be imperceptibly slow. Cations of transition metals play essential roles in the mechanisms of many enzyme-catalyzed reactions. Here we introduce just one representative example, superoxide dismutase. 

C20-0084. In superoxide dismutase it is the Cu center that oxidizes 0. Why is copper more suitable than the center for the role of the oxidizing agent in SOD ... 

The hydroxyl radical plays two essentially different roles (a) as a reactant mediating the transformations of xenobiotics and (b) as a toxicant that damages DNA. They are important in a number of environments (1) in aquatic systems under irradiation, (2) in the troposphere, which is discussed later, and (3) in biological systems in the context of superoxide dismutase and the role of iron. Hydroxyl radicals in aqueous media can be generated by several mechanisms ... 

Touati D, M Jacques, B Tardat, L Bouchard, S Despied (1995) Lethal oxidative damage and mutagenesis are generated by iron Afur mutants of Escherichia coli protective role of superoxide dismutase. J Bacterial 111 2305-2314. 

The heart has a relatively low catalase activity, which, together with the superoxide dismutase (SOD) system, acts to remove hydrogen peroxide and superoxide radicals. In addition, in man, dietary vitamin C plays an important role in the reduction of vitamin E, an intrinsic antioxidant component of biological membranes (Chen and Thacker, 1986 Niki, 1987). Both vitamins C and E can also react directly with hydroxyl and superoxide radicals (HalliwcU and Gutteridge, 1989 Meister, 1992). 

Ito, Y., Hiraishi, H., Razandi, M., Terano, A., Harada, T. and Ivey, K.J. (1992). Role of cellular superoxide dismutase against reactive oxygen metabolite-induced cell dam e in cultured rat hepatocytes. Hepatology 16, 247-254. 

Steer, M.L., Rutledge, P.L., Powers, R.E., Saluja, M. and Saluja, A.K. (1991). The role of oxygen-derived fiee radicals in two models of experimental acute pancreatitis effects of catalase, superoxide dismutase, dimethyl sulphoxide, and allopurinol. Klin. Wochenschr. 69, 1012-1017. 

Takeuchi, K., Nishiwaki, H., Niida, H., Ueshima, K. and Okabe, S. (1991b). Duodenal ulcers induced by diethyl-dithiocarbamate, a superoxide dismutase inhibitor, in the rat role of antioxidative system in the pathogenesis. Jpn. J. Pharmacol. 57, 299-310. 

Imaizumi, S., Woolworth, V., Fishman, R.A. and Chan, P.H. (1989). Superoxide dismutase activities and their role in focal cerebral ischemia. J. Cereb. Blood Flow Metab. 9, S217. 

Ariza ME, Bijur GN, Williams MV. 1998. Lead and mercury mutagenesis Role of H202, superoxide dismutase, and xanthine oxidase. Environ Mol Mut 31 352-361. 

Carloni et al.91 applied the DFT(PZ) calculations to investigate the electronic structure of various models of oxydized and reduced Cu, Zn superoxide dismutase. The first stage of the enzymatic reaction involves the electron transfer from Cu" ion to superoxide. The theoretical investigations provided a detailed description of the electronic structure of the molecules involved in the electron transfer process. The effect of charged groups, present in the active center, on the electron transfer process were analyzed and the Argl41 residue was shown to play a crucial role. 

Misra, H.P. and Fridovich, I. (1972). The role of superoxide anion in the autoxidation of epinephrine and a simple assay for superoxide dismutase. Journal of Biological Chemistry 247 3170-3175. 

In 1965 1967 a great interest has been attached to the possible role of free radicals in cancer after studies by Emanuel and his coworkers who reported the excessive production of free radicals in tumor cells (see, for example, Ref. [145]). On these grounds the authors suggested to apply antioxidant therapy for the treatment of cancer patients. Unfortunately, experimental proofs of overproduction of free radicals in cancer tissue turn out to be erroneous [146], A new interest in the role of free radicals in cancer development emerged after the discovery of superoxide and superoxide dismutases. 

Greenlund, L. J., Deckwerth, T. L. and Johnson, E. M. Jr. Superoxide dismutase delays neuronal apoptosis a role for reactive oxygen species in programmed neuronal death. Neuron 14 303-315,1995. 

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