鬼臼酰肼金属Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ)配合物与DNA分子作用机制的研究

Studies on the Mechanism of the Interaction between Hydrazide-Podophyllic Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ) Metal Complexes and DNA

在pH 7.08 Tris缓冲溶液中,采用粘度测定、电子吸收光谱、凝胶电泳和溴化乙锭荧光分析法研究了鬼臼酰肼(hydrazide-podophyllic,HDPP)NiⅡ,CoⅡ,ZnⅡ金属配合物与小牛胸腺DNA的作用机制,探讨了作用模式。结果发现,当加入一定量的DNA时,配合物的电子吸收光谱的最大吸收峰产生减色效应,同时,DNA也能较大程度地猝灭配合物体系的荧光强度。配合物都能引起DNA粘度的略微增加和将超螺旋DNA切割得到缺刻DNA。所有这些研究表明配合物可能与DNA发生了相互作用,其中镍和钴配合物与DNA之间主要以插入方式相结合;而锌配合物与DNA之间的结合方式为部分插入;求出了三种鬼臼酰肼金属配合物与DNA的结合常数。

The mechanism of the interaction between hydrazide-podophyllic （HDPP） metal （Me） complexes and calf thymus （ct） DNA in Tris buffer （pH 7.08） was studied by viscosity measurements, electronic absorption, gel electrophoresis, and ethidium bromide （EB） fluorescence spectroscopy. The results from varied experiments show that the intensity of the maximal absorption peaks from absorption spectra is weakened in the presence of DNA compared with that in the absence of DNA. Meanwhile, DNA can remarkably quench the emission intensity of the complex Me-HDPP system. The Me-HDPP complexes can increase the viscosity of ct DNA slightly and catalyze the cleavage of super coiled pBR322 DNA to the nicked form. The complexes of Ni-HDPP and Co-HDPP can be bound to ct DNA mainly by interaction, while the partial interaction of Zn-HDPP and ct DNA is the major modes. The binding constant of Me-HDPP complexes with ct DNA was determined.