Formation of S-nitrosothiols via direct nucleophilic nitrosation of thiols by peroxynitrite with elimination of hydrogen peroxide.
Formation of S-nitrosothiols via direct nucleophilic nitrosation of thiols by peroxynitrite with elimination of hydrogen peroxide.
复制标题
通过过氧亚硝酸盐对硫醇进行直接亲核亚硝化并消除过氧化氢，形成 S-亚硝基硫醇。
DOI：
10.1074/jbc.273.46.30255
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Cross,CE
中科院分区：
文献类型：
--
作者：
vanderVliet,A;Hoen,PA;Wong,PS;Bast,A;Cross,CE
过氧亚硝酸盐（ONOO−）是一种由一氧化氮（NO）与超氧阴离子反应形成的强效氧化剂，可以激活鸟苷酸环化酶，并能够通过巯基依赖性NO形成来诱导血管舒张或抑制血小板聚集和白细胞粘附。ONOO−与硫醇的反应被认为是通过形成aS-亚硝基硫醇（亚硝酸盐; RSNO 2）中间体进行的，并产生低水平的S-亚硝基硫醇（亚硝酸盐; RSNO），这两者都是NO的理论来源。ONOO−与GSH反应后NO生成的动力学分析表明，NO生成完全来自亚硫硝酸盐GSNO。进一步的机理研究表明，GSNO的形成ONOO-不发生通过单电子氧化机制。GSH的亚硝化作用理论上可以通过形成硝酸硫酯GSNO 2的中间体来进行，硝酸硫酯GSNO 2在重排为相应的亚硫基硝酸酯（GSONO）后可以与GSH反应形成GSNO和GSOH。然而，在使用NO2·或稳定的亚硝基硫醇叔丁基硫代硝酸酯的实验中，没有发现这种机制的证据。使用高效液相色谱化学发光检测，在有氧和厌氧条件下ONOO−与GSH反应后观察到H2 O2的形成，其水平与GSNO的产率相似，表明直接亲核亚硝化机制与HOO−的消除。我们的研究结果表明，ONOO-可能有助于S-亚硝基化在体内和巯基或其他亲核底物的ONOO-的直接亚硝基化可能是一个重要的，往往被忽视的组成部分NO-生物化学。
Peroxynitrite (ONOO−), a potent oxidant formed by reaction of nitric oxide (NO⋅) with superoxide anion, can activate guanylyl cyclase and is able to induce vasodilation or inhibit platelet aggregation and leukocyte adhesion, via thiol-dependent formation of NO⋅. Reaction of ONOO−with thiols is thought to proceed through formation of aS-nitrothiol (thionitrate; RSNO2) intermediate and yields low levels ofS-nitrosothiols (thionitrites; RSNO), both of which are theoretical sources of NO⋅. Kinetic analysis of NO⋅production after reaction of ONOO−with GSH established that NO⋅originates exclusively from the thionitrite GSNO. Further mechanistic investigations indicated that GSNO formation by ONOO–does not occur via one-electron oxidation mechanisms. Nitrosation of GSH could theoretically proceed via intermediate formation of the thionitrate GSNO2, which, after rearrangement to the corresponding sulfenyl nitrite (GSONO), can react with GSH to form GSNO and GSOH. However, no evidence for such a mechanism was found in experiments with NO2·or with the stable nitrothioltert-butylthionitrate. Using high performance liquid chromatography with chemiluminescence detection, formation of H2O2was observed after reaction of ONOO−with GSH under both aerobic and anaerobic conditions, at levels similar to the yield of GSNO, indicative of a direct nucleophilic nitrosation mechanism with elimination of HOO−. Our results indicate that ONOO−may contribute toS-nitrosationin vivoand that direct nitrosation of thiols or other nucleophilic substrates by ONOO–may represent an important and often overlooked component of NO⋅biochemistry.