Sevilla M D, Becker D, Swarts S, Herrington J
Biochem Biophys Res Commun. 1987 Apr 29;144(2):1037-42. doi: 10.1016/s0006-291x(87)80068-2.
Using Electron Spin Resonance spectroscopy at low temperatures, we find that thiyl radicals resulting from irradiation of frozen aqueous solutions of a variety of thiols, including cysteine, glutathione, and penicillamine react with oxygen to form sulfinyl (RSO.) radicals. The identity of the cysteine sulfinyl radical has been confirmed by the use of molecular oxygen isotopically labeled with 17O. Previous workers have suggested the reaction of thiyl radicals and molecular oxygen resulted in the formation of the potentially damaging thiol peroxyl radical, RSOO.; our work shows no evidence for this species. The sulfinyl radicals are suggested to result from a direct reaction between thiyl radicals and molecular oxygen. This reaction results in the cleavage of the dioxygen bond.
通过在低温下使用电子自旋共振光谱，我们发现，多种硫醇（包括半胱氨酸、谷胱甘肽和青霉胺）的冷冻水溶液经辐照产生的硫自由基会与氧气反应形成亚磺酰基（RSO.）自由基。半胱氨酸亚磺酰基自由基的身份已通过使用用17O同位素标记的分子氧得以确认。先前的研究人员曾提出硫自由基与分子氧的反应会导致形成具有潜在破坏性的硫醇过氧自由基RSOO.；但我们的研究未发现该物种存在的证据。亚磺酰基自由基被认为是硫自由基与分子氧直接反应的产物。该反应导致双氧键的断裂。
