Inhibition of electrocatalytic O(2) reduction of functional CcO models by competitive, non-competitive, and mixed inhibitors.
Inhibition of electrocatalytic O(2) reduction of functional CcO models by competitive, non-competitive, and mixed inhibitors.
复制标题
通过竞争性、非竞争性和混合抑制剂抑制功能性 CcO 模型的电催化 O(2) 还原。
DOI：
10.1021/ic900825y
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发表时间：
2009
影响因子：
4.6
通讯作者：
Decreau,RichardA
中科院分区：
文献类型：
--
作者：
Collman,JamesP;Dey,Abhishek;Barile,ChristopherJ;Ghosh,Somdatta;Decreau,RichardA
在存在几种已知抑制剂如CO、N3 −、CN −和NO2 −的情况下，研究了功能性细胞色素C氧化酶（CcO）模型对O2的电催化还原。这些模型成功地再现了在CcO中观察到的抑制作用，这些抑制剂在相似的浓度下报道。重要的是，数据显示出非常不同的电化学响应，这取决于抑制剂的性质，即竞争性，非竞争性和混合。化学模型已提供这些观察到的电化学行为的差异。使用已知抑制剂的基准电化学行为，研究NO2 −的抑制作用。电化学数据表明，NO2 −在高浓度下起竞争性抑制剂的作用。光谱数据表明，在过量NO2 −存在下，还原催化剂氧化过程中释放的NO是NO2 −竞争性抑制的来源。远端CuBlower的存在降低了CN-和NO2-的抑制作用。而对于CN −，它使其与还原络合物的结合亲和力减弱了约4.5倍，对于NO2 −，它允许通过提出的超氧化物介导的途径从催化失活的、空气稳定的亚硝酰亚铁络合物再生活性催化剂。
Electrocatalytic reduction of O2by functional cytochrome C Oxidase (CcO) models is studied in the presence of several known inhibitors like CO, N3−, CN−, and NO2−. These models successfully reproduce the inhibitions observed in CcO at similar concentrations reported for these inhibitors. Importantly, the data show very different electrochemical responses depending on the nature of the inhibitor, that is, competitive, non-competitive and mixed. Chemical models have been provided for these observed differences in the electrochemical behavior. Using the benchmark electrochemical behaviors for known inhibitors, the inhibition by NO2−is investigated. Electrochemical data suggests that NO2−acts as a competitive inhibitor at high concentrations. Spectroscopic data suggests that NO released during oxidation of the reduced catalyst in presence of excess NO2−is the source of the competitive inhibition by NO2−. Presence of the distal CuBlowers the inhibitory effect of CN−and NO2−. While for CN−it weakens its binding affinity to the reduced complex by ∼4.5 times, for NO2−, it allows regeneration of the active catalyst from a catalytically inactive, air stable ferrous nitrosyl complex via a proposed superoxide mediated pathway.