Monocopper center embedded in a biomimetic cavity: From supramolecular control of copper coordination to redox regulation
Monocopper center embedded in a biomimetic cavity: From supramolecular control of copper coordination to redox regulation
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DOI：
10.1021/ja071219h
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发表时间：
2007-07-18
影响因子：
15
通讯作者：
Le Mest, Yves
中科院分区：
文献类型：
--
作者：
Le Poul, Nicolas;Campion, Morgan;Le Mest, Yves
分析了不同取代的铜-氮-3-杯[6]芳烃类酶“漏斗”络合物的电化学行为。铜(II)/铜(I)氧化还原过程受铜配位的超分子组织调控。“鞋树”烷基腈客体分子在主体腔内的存在是动态氧化还原行为的先决条件。超分子CH-pi与杯芳烃空腔的弱相互作用和N-3取代基(吡啶、咪唑、吡咯烷)的电子/空间效应共同加强了铜的择优几何构型。这决定了电子转移过程的路径，从而决定了氧化还原反应的热力学和动力学。目前的观察结果强烈地回忆起蛋白质基质通过诱导FIT机制、蛋白质折叠、内生和变构效应等生物学概念对铜蛋白质施加的氧化还原控制。
The electrochemical behavior of diversely substituted Cu-N-3-calix[6]arene, enzyme-like, "funnel" complexes is analyzed. The Cu(II)/Cu(I) redox process is regulated by the supramolecular organization of the Cu coordination. The presence of a "shoetree" alkyl nitrile guest molecule inside the host cavity is a prerequisite for a dynamic redox behavior. Combination of supramolecular CH-pi weak interactions with the calixarene cavity and electronic/steric effects from the N-3 substituting groups (pyridine, imidazole, pyrrolidine) enforces the preferential geometrical pattern adopted by Cu. This dictates the pathway of the electron-transfer process and, thus, the thermodynamics and kinetics of the redox reaction in the framework of a square-scheme mechanism. The present observations recall strongly the redox control exerted by the protein matrix on copper proteins through biological concepts such as induced fit mechanism, protein foldings, and entatic and allosteric effects.