Redox state of glutathione in human plasma
Redox state of glutathione in human plasma
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DOI：
10.1016/s0891-5849(99)00275-0
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发表时间：
2000-02-15
影响因子：
7.4
通讯作者：
Sternberg, P
中科院分区：
文献类型：
--
作者：
Jones, DP;Carlson, JL;Sternberg, P
测定了24名25~35岁健康人血浆中谷胱甘肽(GSH)和半胱氨酸(Cys)的硫醇和二硫键形式，并用Nernst方程计算了硫醇/二硫键对的氧化还原电位值(E-h)。尽管GSH的浓度(2.8+/-0.9 mV)远高于GSSG(0.14+/-0.04 mV)，但GSSG/2GSH池的氧化还原电位(-137+/-9 mV)明显高于组织和培养细胞(-185 mV至-258 mV)。这表明GSH在释放到血浆中时会发生快速氧化。个体之间的数值差异非常小，这表明血浆中的还原和氧化速率非常平衡，以保持这种氧化还原电位。半胱氨酸(Cyss)池(-80+/-9 mV)的氧化还原电位增加了57 mV，表明GSSG/2GSH和CySS/2Cys池在血浆中不处于氧化还原平衡。含有CysGly的硫醇/二硫键对的电势介于这些对的电势之间。回归分析表明，个体内不同硫醇/二硫键对的氧化还原电位与Cyss-mono-Gly/(Cys)的E-h相关。CysGly)提供与其他低分子量库以及GSH、CysGly和Cys的蛋白质二硫化物的最佳相关性。这些结果表明，GSSG/2GSH和Cyss-mono-Gly/(Cys.CysGly)可能在临床和流行病学研究中提供定量表达氧化/抗氧化平衡的有用手段。(C)2000年爱思唯尔科学公司。
Thiol and disulfide forms of glutathione (GSH) and cysteine (Cys) were measured in plasma from 24 healthy individuals aged 25-35 and redox potential values (E-h) for thiol/disulfide couples were calculated using the Nernst equation. Although the concentration of GSH (2.8 +/- 0.9 mu M) was much greater than that of GSSG (0.14 +/- 0.04 mu M), the redox potential of the GSSG/2GSH pool (-137 +/- 9 mV) was considerably more oxidized than values for tissues and cultured cells (-185 to -258 mV). This indicates that a rapid oxidation of GSH occurs upon release into plasma. The difference in values between individuals was remarkably small, suggesting that the rates of reduction and oxidation in the plasma are closely balanced to maintain this redox potential. The redox potential for the Cys and cystine (CySS) pool (-80 +/- 9 mV) was 57 mV more oxidized, showing that the GSSG/2GSH and the CySS/2Cys pools are not in redox equilibrium in the plasma. Potentials for thiol/disulfide couples involving CysGly were intermediate between the values for these couples. Regression analyses showed that the redox potentials for the different thiol/disulfide couples within individuals were correlated, with the E-h for CySS-mono-Gly/(Cys . CysGly) providing the best correlation with other low molecular weight pools as well as protein disulfides of GSH, CysGly and Cys. These results suggest that E-h values for GSSG/2GSH and CySS-mono-Gly/(Cys . CysGly) may provide useful means to quantitatively express the oxidant/antioxidant balance in clinical and epidemiologic studies. (C) 2000 Elsevier Science Inc.