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2316001 
Journal Article 
Abstract 
Nitric oxide and nitroxides can act as efficient scavengers of protein-derived free radicals 
Lam, MA; Pattison, DI; Bottle, SE; Keddie, DJ; Davies, MJ 
2008 
Yes 
Free Radical Biology and Medicine
ISSN: 0891-5849
EISSN: 1873-4596 
45 
Suppl. 
S113-S113 
English 
WOS:000260867900320 
is part of a larger document 3452652 SFRBM's 15th Annual Meeting: Program and Abstracts
Nitric oxide (•NO) may act as either a pro- or anti-oxidant in biological systems. Although •NO and nitroxide radicals react slowly with most molecules, they react at near diffusion-controlled rates with other radicals and may therefore be efficient protective agents. This study assessed the ability of •NO and nitroxides to intercept specific protein-derived radicals, and compared the efficacy of these species. Three protein radical systems were investigated: BSA-derived radicals generated via radical transfer from H2O2-activated horseradish peroxidase; radicals formed on myoglobin via reaction with H2O2; and carbon-centred radicals formed from amino-acid hydroperoxides on exposure to Fe2+- EDTA. in each case radicals were generated in the absence or presence of •NO or nitroxides of different size and charge. Concentration-dependent loss of the protein radicals was detected by EPR with both •NO and nitroxides, and time-dependent consumption of •NO using an •NO electrode. The protein oxidation product dityrosine was significantly reduced by •NO and nitroxides, and DOPA levels were reduced by nitroxides but not •NO. Overall, these studies demonstrate that •NO and nitroxides are efficient scavengers of protein radicals, and hence are potential protective agents against protein oxidation reactions and the resulting damage. These reactions show little dependence on nitroxide structure or charge. 
Society for Free Radical Biology and Medicine 15th Annual Meeting 
Indianapolis, IN 
November 19-23, 2008