邻菲咯啉-铜(Ⅱ)-L-亮氨酸配合物与DNA的结合

Studies on the Interaction between Ternary Copper(Ⅱ) Complex with Phenanthroline and L-Leucine Ligands and DNA

应用循环伏安法、微分脉冲伏安法、电子吸收光谱和溴化乙锭 (EB)荧光分析法研究了[Cu(phen) (H2 O) (L Leu) + ](phen=1 ,1 0 邻菲咯啉 ,L Leu =L 亮氨酸 )与小牛胸腺DNA的相互作用。结果发现中心铜离子在循环伏安图上呈现一对明显的准可逆氧化还原波。当加入一定量的DNA时 ,配合物的氧化还原峰电流明显降低 ,配位阳离子的扩散系数减小 ,电子光谱的最大吸收峰明显红移 ,产生明显的减色效应。同时 ,配合物也能较大程度地猝灭EB DNA体系的荧光 ,证明配合物与DNA存在插入结合。

The interaction between [Cu(phen)(H 2O)(L-Leu)](phen=1,10-phenanthroline and L-Leu=L-Leucine)and calf thymus DNA has been investigated by cyclic voltammetry,differential pulse voltammetry,electronic absorption and ethidium bromide(EB) fluorescene spectroscopy.A quasi-reversible redox wave for the central copper ion from the cyclic voltammograms is shown at a platinum electrode.It has been found that the values of the reduction peak current and apparent diffusion coefficientare are decreased significantly in the presence of DNA compared with that in the absence of DNA,the max.absorption peaks from absorption spectra are red-shifted and the intensity is weakened.At the same time,[Cu(phen)(H 2O)(L-Leu)] can remarkably quench the emission intensity of EB-DNA system.The intercalation mode between the complex and DNA is proved to exist.