A superoxide dismutase mimic with high activity: crystal structure, solution equilibrium and pulse radiolysis
作者:Jian-Jun Zhang、Qin-Hui Luo、De-Liang Long、Jiu-Tong Chen、Feng-Mei Li、An-Dong Liu
DOI:10.1039/a909018e
日期:——
A new binuclear copper(II) complex [Cu2(H−4tapt)]·10H2O, where tapt is N,N′,N′′,N′′′-tetra(2-aminopropyl)-1,1,2,2-ethanetetraamide, has been synthesized and investigated in detail as a mimic of superoxide dismutase. Crystal structure analysis shows that each copper atom is situated in a slightly distorted square-pyramidal environment, with a water molecule at the apex. According to the result of pulse radiolysis, the complex has a high rate constant toward ˙O2−, kcat = 1.91 × 108 dm3 mol−1 s−1 (pH 7.4). Potentiometric titration shows that the mimic exhibits high stability at physiological pH value (7.4). EPR and ES-MS spectra reveal intermolecular interaction of two copper(II) nuclei.
一种新的双核铜(II)配合物[Cu2(H−4tapt)]·10H2O,其中tapt为N,N',N'',N'''-四(2-氨基丙基)-1,1,2,2 -乙四酰胺,已作为超氧化物歧化酶的模拟物被合成和详细研究。晶体结构分析表明,每个铜原子都位于一个稍微扭曲的方锥体环境中,顶部有一个水分子。根据脉冲放射分解的结果,该络合物对˙O2−具有较高的速率常数,kcat = 1.91 × 108 dm3 mol−1 s−1 (pH 7.4)。电位滴定表明模拟物在生理pH值(7.4)下表现出较高的稳定性。 EPR 和 ES-MS 谱揭示了两个铜 (II) 核的分子间相互作用。