光谱法研究普利沙星与小牛胸腺DNA的结合作用

利用紫外光谱,荧光光谱及流体动力学方法,研究了普利沙星与小牛胸腺DNA的作用机理.讨论了不同浓度普利沙星与DNA作用的紫外光谱,荧光光谱,磷酸盐效应以及离子强度对两者相互作用的影响,测量了DNA的热变性温度和粘度.从紫外光谱图上看出DNA发生了明显的减色效应,说明普利沙星可能与DNA发生作用.普利沙星的荧光光谱发生了有规律的猝灭,最大发射峰发生红移,猝灭常数为3.1×104 L·mol-1,为静态猝灭,表明普利沙星与DNA结合生成了二元复合物.磷酸盐效应表明普利沙星与DNA的磷酸基团不发生静电作用.普利沙星引起了DNA的热变性温度略微升高(≤7℃)和DNA粘度略微下降,表明普利沙星与DNA之间不存在插入作用,只是在DNA的外部发生沟槽作用.

Spectroscopic Studies on the Binding of Prulifloxacin and ct-DNA

The interaction mechanism of prulifloxacin (PL) and calf thymus DNA (ct-DNA) was studied by UV spectra, fluorescence spectra, and hydrodynamic measurements. The binding of ct-DNA and different concentrations of PL was discussed with UV, FL, phosphate effect and ion strength. The denaturation temperature and viscosity were measured. It is obvious that there is a hypochromic effect on the UV spectra with the fluorescence intensity decreasing regularly after addition of DNA and a red shift of the maximum emission peak with a static quenching constant of 3.1 x 10(4) L x mol(-1). The above results show that a binary complex forms between PL and DNA. It is indicated that there is no static-electro interaction between them by phosphate effect. The outer groove binding is suggested by denaturation temperature of DNA increasing (no more than 7 degrees C) and viscosity slightly decreasing.