Mottley C, Mason R P
Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Arch Biochem Biophys. 1988 Dec;267(2):681-9. doi: 10.1016/0003-9861(88)90077-x.
The one-electron oxidation of (bi)sulfite is catalyzed by peroxidases to yield the sulfur trioxide radical anion (SO3-), a predominantly sulfur-centered radical as shown by studies with 33S-labeled (bi)sulfite. This radical reacts with molecular oxygen to form a peroxyl radical. The subsequent reaction of this peroxyl radical with (bi)sulfite has been proposed to form the sulfate anion radical, which is nearly as strong an oxidant as the hydroxyl radical. We used the spin trapping electron spin resonance technique to provide for the first time direct evidence for sulfate anion radical formation during (bi)sulfite peroxidation. The sulfate anion radical is known to react with many compounds more commonly thought of as hydroxyl radical scavengers such as formate and ethanol. Free radicals derived from these scavengers are trapped in systems where (bi)sulfite peroxidation has been inhibited by these scavengers.
过氧化物酶催化（亚）硫酸氢盐的单电子氧化反应，生成三氧化硫自由基阴离子（SO3-），如用33S标记的（亚）硫酸氢盐研究所示，这是一种主要以硫为中心的自由基。该自由基与分子氧反应形成过氧自由基。有人提出，该过氧自由基随后与（亚）硫酸氢盐反应形成硫酸根阴离子自由基，其氧化性几乎与羟基自由基一样强。我们使用自旋捕捉电子自旋共振技术，首次为（亚）硫酸氢盐过氧化过程中硫酸根阴离子自由基的形成提供了直接证据。已知硫酸根阴离子自由基会与许多通常被认为是羟基自由基清除剂的化合物发生反应，如甲酸和乙醇。在这些清除剂抑制（亚）硫酸氢盐过氧化的体系中，来自这些清除剂的自由基会被捕获。
