Winterbourn Christine C, Kettle Anthony J
Free Radical Research, Department of Pathology, Christchurch School of Medicine and Health Sciences, P.O. Box 4345, Christchurch, New Zealand.
Biochem Biophys Res Commun. 2003 Jun 6;305(3):729-36. doi: 10.1016/s0006-291x(03)00810-6.
Superoxide reacts with many radicals, such as phenoxyl radicals, at near diffusion-controlled rates. These reactions are usually considered to be repair processes and have received little biological attention. However, addition of superoxide to give hydroperoxides and secondary oxidation products can also occur. The relative contributions of addition and repair vary depending on the properties of the phenol. With tyrosine, addition to give tyrosine hydroperoxide predominates, but in peptides the efficiency of hydroperoxide formation depends on the proximity of free amine groups. Radicals from other phenolic compounds, such as alpha-tocopherol and serotonin, also undergo addition reactions with superoxide. Physiologically, these reactions are likely to be more significant than dimerization when both radicals are generated together. They warrant attention as potential contributors to superoxide toxicity.
超氧化物与许多自由基，如苯氧自由基，以接近扩散控制的速率发生反应。这些反应通常被认为是修复过程，很少受到生物学关注。然而，超氧化物加成生成氢过氧化物和二次氧化产物的情况也会发生。加成和修复的相对贡献因酚类的性质而异。对于酪氨酸，生成酪氨酸氢过氧化物的加成反应占主导，但在肽中，氢过氧化物形成的效率取决于游离胺基的 proximity。其他酚类化合物，如α-生育酚和血清素产生的自由基，也会与超氧化物发生加成反应。在生理上，当两种自由基同时产生时，这些反应可能比二聚化更重要。它们作为超氧化物毒性的潜在贡献者值得关注。
