Is vanadate reduced by thiols under biological conditions? Changing the redox potential of V(V)/V(IV) by complexation in aqueous solution.
Is vanadate reduced by thiols under biological conditions? Changing the redox potential of V(V)/V(IV) by complexation in aqueous solution.
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DOI：
10.1021/ic100080k
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发表时间：
2010-05-03
影响因子：
4.6
通讯作者：
Roberts, Chris R.
中科院分区：
文献类型：
--
作者：
Crans, Debbie C.;Zhang, Boyan;Gaidamauskas, Ernestas;Keramidas, Anastasios D.;Willsky, Gail R.;Roberts, Chris R.
虽然教条认为钒酸盐很容易被谷胱甘肽、半胱氨酸和其他硫醇还原，但有几个例子证明钒(V)-硫复合物可以形成并被观察到。这个难题已经困扰了生命科学家20多年。研究这个问题需要了解钒（IV）和钒(V)以及水溶液中具有代表性的硫醇形成的配合物。采用多核磁共振、EPR和紫外可见光谱研究了钒酸盐和水合钒基阳离子与2-巯基乙醇的反应。在中性和碱性条件下，钒酸盐与2-巯基乙醇形成稳定的2:2的络合物。相反，钒酸盐可以氧化2-巯基乙醇；该过程在低pH和高溶质浓度条件下更有利。在钒（IV）和2-巯基乙醇之间形成的络合物具有1:2的化学计量，并且可以在高pH和高2-巯基乙醇浓度下观察到。推导了溶液结构，并绘制了形态图。这项工作证明了钒（IV）和(V)-硫醇配合物的形成和氧化还原化学也发生了。钒酸盐是否发生还原是由一系列参数决定的：pH、溶质和钒酸盐浓度以及其他络合配体的存在。基于这些结果，现在有可能了解钒在谷胱甘肽、半胱氨酸和其他硫醇存在下的氧化态（IV）和氧化态(V)的分布，并开始评估发挥特定生物效应的钒化合物的形式，包括胰岛素增强剂、抗阿米巴药物和与钒结合蛋白的相互作用。
Although dogma states that vanadate is readily reduced by glutathione, cysteine and other thiols, there are several examples documenting that vanadium(V)-sulfur complexes can form and be observed. This conundrum has impacted life scientists for more than two decades. Investigation of this problem requires an understanding of both the complexes that form from vanadium(IV) and (V) and a representative thiol in aqueous solution. The reactions of vanadate and hydrated vanadyl cation with 2-mercaptoethanol have been investigated using multinuclear NMR, EPR and UV-vis spectroscopy. Vanadate forms a stable complex of 2:2 stoichiometry with 2-mercaptoethanol at neutral and alkaline pH. In contrast, vanadate can oxidize 2-mercaptoethanol; this process is favored at low pH and high solute concentrations. The complex that forms between aqueous vanadium(IV) and 2-mercaptoethanol has a 1:2 stoichiometry and can be observed at high pH and high 2-mercaptoethanol concentration. The solution structures have been deduced and speciation diagrams prepared. This work demonstrates that both vanadium(IV) and (V)-thiol complexes form and that redox chemistry also takes place. Whether reduction of vanadate takes place is governed by a combination of parameters: pH, solute- and vanadate-concentrations and the presence of other complexing ligands. Based on these results it is now possible to understand the distribution of vanadium in oxidation states (IV) and (V) in the presence of glutathione, cysteine and other thiols and begin to evaluate the forms of the vanadium compounds that exert a particular biological effect including the insulin-enhancing agents, anti-amoebic agents and interactions with vanadium binding proteins.
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影响因子：
4.6
作者：
Chu, WC;Wu, CC;Hsu, HF
通讯作者：
Hsu, HF
影响因子：
4.6
作者：
Crans, DC;Jiang, FL;Miller, MM
通讯作者：
Miller, MM
影响因子：
15
作者：
CRANS, DC;RITHNER, CD;THEISEN, LA
通讯作者：
THEISEN, LA
DOI：
10.1139/cjc-77-12-2088
发表时间：
1999-12-01
期刊：
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE
影响因子：
--
作者：
Bhattacharyya, S;Batchelor, RJ;Tracey, AS
通讯作者：
Tracey, AS
影响因子：
7.3
作者：
Adachi, Yusuke;Yoshida, Jiro;Sakurai, Hiromu
通讯作者：
Sakurai, Hiromu