荧光探针法研究百草枯与DNA的相互作用

以中性红（NR）为分子探针,应用紫外光谱法和荧光光谱法研究了除草剂百草枯（PQ）与小牛胸腺DNA（ctDNA）之间的相互作用。在pH7.3的Tris-HCl（5×10-2mol.L-1）缓冲溶液中,NR分子主要以嵌插方式结合到ctDNA双螺旋结构上,百草枯的加入抑制了NR与ctDNA之间的结合,用Stern-Volmer方程进行数据处理,表明百草枯对ctDNA-NR的荧光猝灭不是单纯的静态或动态猝灭方式,属于混合型的。综合紫外光谱、离子强度等研究证实,在该实验条件下,百草枯与DNA之间存在静电和嵌插两种作用。

Study on the Interaction Between Paraquat and DNA by Fluorescent Probe

The interaction between paraquat and ctDNA was studied using neutral red（NR） as a fluorescence probe by ultraviolet spectra and fluorescence spectra.At pH 7.3 Tris-HCl buffer solutions,NR primarily bound to double helical structure of ctDNA through intercalation method,and the interaction between NR and ctDNA was restrained by paraquat.The experimental data were plotted by Stern-Volmer equation which indicated that the fluorescence quenching of ctDNA-NR by paraquat was not only static quenching or dynamic quenching,but mixed type quenching.Both experiments of ultraviolet absorption spectrum and fluorescence spectrum indicated that there were electrostatic attraction and intercalation between paraquat and DNA.