Oxidative superoxide dismutase

As would be expected, several additional applications of cryoprobe technology in the area of biomacromolecular NMR were also published. Goger et al,253 described the reduction in time required for the acquisition of triple resonance NMR experiments performed on proteins. Later in the year, Craik et al.254 reported a study of the 21 amino acid bacterial peptide microcin J25 that relied on cryoprobe technology. In late 2003, Bertini and co-workers255 reported the application of cryoprobe-based 13C direct-detection NMR experiments on a paramagnetic oxidized superoxide dismutase. 

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. 

Propyl gallate is an antioxidant. It protects against oxidation by hydrogen peroxide and oxygen free radicals in a catalytic manner similar to superoxide dismutase. 

Oxidant production is measured with the fluorogenic substrate para-hydroxyphenylacetic acid (PHPA) in the presence of superoxide dismutase and peroxidase (9). Under these conditions, superoxide is converted to H2O2 by the superoxide dismutase, and two molecules of PHPA are converted to a fluorescent diadduct by H2O2 and peroxidase. Similar assays have been devised using homovanillic acid (16) or scopoletin (17) instead of PHPA. 

Superoxide is formed (reaction 1) in the red blood cell by the auto-oxidation of hemoglobin to methemo-globin (approximately 3% of hemoglobin in human red blood cells has been calculated to auto-oxidize per day) in other tissues, it is formed by the action of enzymes such as cytochrome P450 reductase and xanthine oxidase. When stimulated by contact with bacteria, neutrophils exhibit a respiratory burst (see below) and produce superoxide in a reaction catalyzed by NADPH oxidase (reaction 2). Superoxide spontaneously dismu-tates to form H2O2 and O2 however, the rate of this same reaction is speeded up tremendously by the action of the enzyme superoxide dismutase (reaction 3). Hydrogen peroxide is subject to a number of fates. The enzyme catalase, present in many types of cells, converts... 

The red cell contains a battery of cytosolic enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, to dispose of powerful oxidants generated during its metabolism. 

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 ... 

Bebien M, G Lagniel, J Garin, D Touati, A Vermeglio, J Labarre (2002) Involvement of superoxide dismutases in the response of Escherichia coli to selenium oxides. J Bacterial 184 1556-1564. 

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. 

Verspaget, H.W., Pena, A.S., Weterman, I.T. and Earners, C.B.H.W. (1988). Diminished neutrophil function in Crohn s disease and ulcerative colitis identified by decreased oxidative metabolism and low superoxide dismutase content. Gut 29, 223-228. 

Collier et al. (1990) extended their studies relating to oxidative stress and diabetes by demonstrating that the levels of several free-radical scavengers (red cell superoxide dismutase, plasma thiols) were significantly reduced in 22 type 2 diabetic patients (mean age 53 years) in comparison with 15 control subjects (mean age 51 years). No significant diflFerences in red cell lysate thiols or... 

Freeman, B.A., Turrens, J.F., Mirza, Z., Crapo, J.D. and Young, S.L. (1985). Modulation of oxidant lung injury by using liposome-entrapped superoxide dismutase and catalase. Fed. Proc. 44, 2591-2595. 

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