• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >The copper(II)-catalyzed oxidation of glutathione
【24h】

The copper(II)-catalyzed oxidation of glutathione

机译：铜（II）催化的谷胱甘肽氧化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The kinetics and mechanisms of copper(II)-catalyzed GSH oxidation are examined in the light of its biological importance and in the use of blood and/or saliva sample for GSH monitoring. The rates of 'free thiol' consumption were measured spectrophotometrically via reaction with DTNB, showing that GSH is not auto-oxidized by oxygen in the absence of a catalyst. In the presence of Cu2+, reactions with two timescales were observed. The first step (short timescale) involves the fast formation of a copper-glutathione complex via the cysteine thiol. The second step (longer timescale) is the overall oxidation of GSH to GSSG catalyzed by copper(II). When the initial concentrations of GSH are at least three-fold in excess of Cu2+, the rate law is deduced to be. d[thiol]/dt = k[copper. glutathione complex][O-2](0.5)[H2O2]. 0.5. The order of reaction with respect to O-2 of 0.5th reveals a pre-equilibrium prior to the rate-determining step of GSSG formation. In contrast to [Cu2+] and [O-2], the rate of reactions decreases with increasing concentrations of GSH. This inverse relationship is proposed to be a result of competing formation of an inactive form of copper-glutathione complex (binding to glutamic and/or glycine moieties).
机译：鉴于其生物学重要性以及使用血液和/或唾液样品进行GSH监测，研究了铜（II）催化的GSH氧化的动力学和机理。通过与DTNB的反应用分光光度法测量了“游离硫醇”的消耗速率，这表明GSH在没有催化剂的情况下不会被氧气自动氧化。在Cu 2+存在下，观察到具有两个时间尺度的反应。第一步（较短的时间范围）涉及通过半胱氨酸硫醇快速形成铜-谷胱甘肽复合物。第二步（更长的时间）是铜（II）催化将GSH整体氧化为GSSG。当GSH的初始浓度至少超过Cu2 +的三倍时，可以推定速率定律为。 d [硫醇] / dt ＝ k [铜。谷胱甘肽复合物] [O-2]（0.5）[H2O2]。 0.5。相对于O-2的反应顺序为0.5，表明在GSSG形成速率确定步骤之前先达到了平衡。与[Cu2 +]和[O-2]相反，反应速率随GSH浓度的增加而降低。提出这种逆关系是竞争性形成非活性形式的铜-谷胱甘肽复合物（结合谷氨酸和/或甘氨酸部分）的结果。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号