电化学方法研究(phen)2Cu2+配合物与DNA的相互作用

用电化学循环伏安法和微分脉冲伏安法研究了1，10-邻菲咯啉铜配合物（phen）2Cu^2＋]与小牛胸腺DNA（CTDNA）的相互作用。结果发现，在pH=7．4的三羟甲基胺基甲烷-盐酸缓冲溶液（Tris—HCl）中，（phen）2Cu^2＋配合物的铜离子在循环伏安图上呈现明显的准可逆氧化-还原波。当加入一定量的小牛胸腺DNA时，配合物（phen），Cu^2＋的氧化和还原峰电流均有所下降。通过比较（phen）2Cu^2＋配合物中加入单链DNA和双链DNA后的氧化和还原峰电流下降的程度，前者比后者F降的程度小，可以得出（phen）2Cu^2＋配合物与小牛胸腺双链DNA的作用方式存在着插入式的沟槽结合模式。这个结论在本实验中由盐效应进一步得到证实。由此可知，（phen）2Cu^2＋配合物与小牛胸腺DNA形成了一种插入式的电惰性结合物，从而导致氧化还原峰电流下降。

The Interaction between Copper(Ⅱ) Complex with 1,10-Phenanthroline and DNA by Electrochemical Techniques

The interaction between the complex of(phen)_2Cu~(2+)(phen=1,10-phenanthroline) and calf thymus DNA has been investigated by cyclic voltammetry(CV) and differential pulse voltammetry(DPV).A quasi-reversible redox wave for the central copper ion of the complex can be obtained at a glassy carbon electrode with CV.It was found that the DPV and CV redox peak current decreased significantly in the presence of DNA as compared with that in the absence of DNA.The interactions between(phen)_2Cu~(2+) and double stranded DNA,and that between(phen)_2Cu~(2+) and single stranded DNA,were investigated by CV.Comparing their decreasing degrel of the redox peak current,the interaction pattern of former one was intercalation.And this result was also proved reasonable by the experiment of salt effect.All experimental results indicated that the complex of(phen)_2Cu~(2+) and double stranded DNA form a kind of intercalary inert combinations so that their redox peak current decreases.