Superoxide dismutase electron paramagnetic resonance

BH4 = Tetrahydrobiopterin CAM = Cytotoxic activated macrophage cNOS = Constitutive nitric oxide synthase CPR = Cytochrome P450 reductase EDRF = Endothelial-derived relaxation factor EPR = Electron paramagnetic resonance spectroscopy IL-1 = Interleukin-1 iNOS = Inducible nitric oxide synthase EPS = Lipopolysaccharide, or endotoxin NMMA = ISp-monomethyl-L-arginine NOS = Nitric oxide synthase ROS = Reactive oxygen species SOD = Superoxide dismutase TNF = Tumor necrosis factor. 

Both charge isomers have a relative molecular mass of32,000 daltons. The isomerism is attributed to the different isoelectric points of the proteins No differences were found in metal content, antigenicity, electron paramagnetic resonance and electron absorption spectroscopy Holo- and apo-superoxide dismutase, which have electro-... 

Bronchoalveolar lavage cells (lx 10 ) suspended in Dulbecco s phosphate buffered saline (0.5 ml) containing 5,5-dimethyl-l-pyrroline-1-oxide (DMPO 100 mM) in duplicate samples, one with and one without superoxide dismutase (500 imits/ml) by electron paramagnetic resonance measurements recorded superoxide anion generation at sites of antigen challenge (Sanders et al. 1995). 

Yang 1981). Support for the theory of alkyl radical transfer was provided by Ortiz de Monellano et al. (1983) who used the electronic paramagnetic resonance spin-trapping technique to detect the 2-phenylethyl radical formed during microsomal biotransformation of phenelzine. Production of the a-(4-pyridyl 1 -oxide)-N-ferf-butylnitrone/2-phenyl-ethyl radical adduct was dependent on the presence of active microsomes, phenelzine, NADPH (or NADH), and spin trap a-(4-pyridyl l-oxide)-N-ferf-butylnitrone (Ortiz de Monellano et al. 1983). The addition of catalase and superoxide dismutase resulted in a 28.5 and 24 % decrease in radical production, respectively (Rumyantseva et al. 1991). The concentration of the a-(4-pyridyl l-oxide)-N-ferf-butylnitrone/2-phenylethyl radical adduct decreased significantly in the presence of metal chelators, i.e. EDTA, diethylenetriaminepentaacetic acid (DTPA), or deferoxamine mesylate. 

Microglia, when stimulated by phorbol ester or opsonified zymosan, gave rise to electron paramagnetic resonance spectra characteristic of superoxide (Sankarapandi etal. 1998). Experiments performed in the presence of superoxide dismutase, catalase, deferoxamine, and dimethyl sulfoxide excluded generation of hydroxyl radicals in significant amounts. Microglial superoxide generation was blocked by the NADPH oxidase inhibitor di-phenylene iodonium in a manner similar to that... 

Using various free radical scavenging systems. Jolly et al. (1984), Burton (1985), Ambrosio et al. (1986), Bolli et al. (1987) and Bhatnagar (1995) have shown a link between myocardial ischaemia and reperfusion injury and the generation of various toxic free radical species. Sharma et al. (1994) in an electron paramagnetic resonance study found ascorbyl free radical as a real-time marker of free radical generation in briefly ischaemic and reper-fused dog hearts. Only Uraize et al. (1987) were unable to limit the size of myocardial necrosis after 40 min of ischaemia by superoxide dismutase. 

Lieberman RA, Sands RH, Fee JA. 1982. A study of the electron paramagnetic resonance properties of single monocbnic crystals of bovine superoxide dismutase. J Biol Chem 257 336-344. 

Kamnakaran, C., Zhang, H., Crow, J.P., Anthohne, W.E., Kalyanaraman, B., 2004. Direct probing of copper active site and free radical formed during bicarbonate-dependent peroxidase activity of bovine and human copper, zinc-superoxide dismutases. Low-temperature electron paramagnetic resonance and electron nuclear double resonance studies. J. Biol. Chem. 279, 32534—32540. 

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