光谱法研究邻菲罗啉锌与DNA的相互作用

Spectroscopic Studies on the Interaction Between Zn(phen)_3^(2+) and Calf Thymus DNA

在模拟人体生理条件下(pH 7.4),运用荧光光谱和紫外可见吸收光谱研究了邻菲罗啉锌(Zn(phen)2+3)与小牛胸腺DNA(ctDNA)之间的相互作用。研究结果显示,ctDNA对Zn(phen)2+3的荧光猝灭机制属于静态猝灭。根据修正的Stern-Vomer方程计算了不同温度下的结合常数,并结合Van′t Hoff方程计算出相应的热力学参数,焓变值(ΔH=-7.029kJ/mol)和熵变值(ΔS=50.631J/(mol·K)表明静电作用力是维持Zn(phen)2+3-ctDNA复合物稳定的主要作用力。此外离子强度实验和KI荧光猝灭实验也证实了Zn(phen)2+3与ctDNA间通过静电作用的方式结合,而不是沟槽作用和嵌插作用。

The interaction between Zn（Ⅱ）-1,10-pheneanthroline（Zn（phen）2＋3）and calf thymus DNA（ctDNA）under the simulative physiological conditions（pH7.4）was investigated by fluorescence spectroscopy and UV-vis absorption spectroscopy.The fluorescence data showed that the mechanism of Zn（phen）2＋3 quenched by ctDNA was static quenching.The binding constants at different temperatures were calculated by the modified Stern-Vomer equation.The thermodynamic parameters determined by Van′t Hoff equation indicated that electrostatic force played a dominant role in the stability of Zn（phen）2＋3-ctDNA complex.In addition,ionic strength experiments and KI experiments corroborated that Zn（phen）2＋3and ctDNA were combined by means of electrostatic interaction,rather than the grooves interaction or intercalation interaction.