Synthesis and X-ray absorption spectroscopy structural studies of Cu(I) complexes of HistidylHistidine peptides: The predominance of linear 2-coordinate geometry
Synthesis and X-ray absorption spectroscopy structural studies of Cu(I) complexes of HistidylHistidine peptides: The predominance of linear 2-coordinate geometry
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DOI：
10.1021/ja0708013
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发表时间：
2007-05-02
影响因子：
15
通讯作者：
Karlin, Kenneth D.
中科院分区：
文献类型：
--
作者：
Himes, Richard A.;Park, Ga Young;Karlin, Kenneth D.
修饰的His-His二肽已与铜（I）盐反应，以模拟某些氧活化铜蛋白以及淀粉样β-肽中由连续His残基结合的活性位点Cu离子。通过这些配体螯合铜（I），得到线性的二配位络合物，其结构通过X-射线吸收光谱研究。复合物对氧化是稳健的，显示出有限的与O-2的反应性，并且它们与CO的结合较弱。与第三个配体（N-甲基咪唑）的反应提供了一个显着不同的结构（扭曲的T形）和反应性，结合CO和氧化后迅速暴露于分子氧的配合物。
Modified His-His dipeptides have been reacted with copper(I) salts to model active-site Cu ions bound by contiguous His residues in certain oxygen-activating copper proteins, as well as amyloid beta-peptide. Chelation of copper(I) by these ligands affords linear, two-coordinate complexes as studied structurally by X-ray absorption spectroscopy. The complexes are robust toward oxidation, showing limited to no reactivity with O-2, and they bind CO weakly. Reaction with a third ligand (N-methylimidazole) affords complexes with a markedly different structure (distorted T-shaped) and reactivity, binding CO and oxidizing rapidly upon exposure to dioxygen.