Electroreduction of nitrite to nitrogen oxide by a copper-containing nitrite reductase model complex incorporated into collagen film
Electroreduction of nitrite to nitrogen oxide by a copper-containing nitrite reductase model complex incorporated into collagen film
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DOI：
10.1016/j.bioelechem.2009.06.013
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发表时间：
2010-02-01
影响因子：
5
通讯作者：
Yamaguchi, Kazuya
中科院分区：
文献类型：
--
作者：
Isoda, Naoko;Yokoyama, Hiroshi;Yamaguchi, Kazuya
研究了胶原膜中掺入含铜亚硝酸还原酶活性中心的CuME(2)bpaCl2对亚硝酸根还原为NO的电催化作用。CuM(2)bpaCl(2)在胶原基质中的77-K EPR谱显示出典型的四方Cu2+生色团的轴向信号(g(//)=2.26，g(垂直)=2.05，A(//)=16.4mT)。在pH为5.5时，氧化还原电位为-63 mV(Delta E=72 mV)，这与Cu2+/Cu2+对有关。在亚硝酸盐存在下，CuME(2)bpaCl(2)在胶原基质中的循环伏安曲线上的阴极电流增大。当达到-300 mV时，CuME(2)bpaCl(2)/胶原膜涂层电极上观察到NO的线性产生。用Michaelis-Menten方程分析了NO生成速率与溶液中亚硝酸盐浓度的关系，其中V-max=3.16nM S(-1)，K-m=1.1 mm(pH=5.5)。电流的增加和反应速度取决于溶液的pH值。铜络合物在胶原基质中还原亚硝酸根的机理与酶在水溶液中的还原机理相同。(C)2009爱思唯尔B.V.保留所有权利。
The electrocatalytic reduction of nitrite to NO by CuMe(2)bpaCl(2), which is a model for the active site of copper-containing nitrite reductase, incorporated into collagen film was investigated. The 77-K EPR spectrum of CuMe(2)bpaCl(2) in the collagen matrix revealed the typical axial signals (g(//)=2.26, g(perpendicular to)=2.05, A(//)=16.4mT) of a tetragonal Cu2+ chromophore. The redox potential, which is related to the Cu+/Cu2+ couple, was -63 mV (Delta E= 72 mV) at pH 5.5. In the presence of nitrite, an increase in the cathodic current was observed in the cyclic voltammogram of CuMe(2)bpaCl(2) in the collagen matrix. Upon reaching - 300 mV, a linear generation of NO was observed for the CuMe(2)bpaCl(2)/collagen film-coated electrode. The relationship between the rate of NO generation and the nitrite concentration in solution was analyzed using the Michaelis-Menten equation, where V-max = 3.16 nM s(-1) and K-m = 1.1 mM at pH 5.5. The current increase and the reaction rate were dependent on the pH of the solution. The mechanism of nitrite reduction by the copper complex in the collagen matrix was the same mechanism as that of the enzyme in aqueous solution. (c) 2009 Elsevier B.V. All rights reserved.