甲基丙烯酸-8-羟基喹啉-Eu(Ⅲ)配合物与鲱鱼精DNA的作用机制

Mechanism of Interaction between Eu(Ⅲ) Complex with Methacrylic Acid-8-hydroxyquinoline and Herring Sperm DNA

采用光谱法、黏度法和DNA热变性方法研究甲基丙烯酸8羟基喹啉Eu(Ⅲ)配台物(Eu(MA)_2(hq))与鲱鱼精DNA之间的作用机制和结台常数结果表明:该配台物加人鲱鱼精DNA后,特征吸收峰发生明显的减色效应,但峰位红移现象不明显;该配台物能猝灭中性红DNA体系的荧光;该配台物与鲱鱼精DNA的结台常数K_(20)=5.91×10~3L/mol,K_(35)=7.70×10~3L/mol,二者作用的物质的量比为1;该配台物与鲱鱼精DNA之间的热力学函数△rH_m^e=1.34×10~3J/mol,△rG_m^e=-2.12×10~4J/mol,△rS_m^e=76.41 J/(mol·K);鲱鱼精DNA的相对黏度增大,熔点明显升高,Eu(MA)_2(hq)与鲱鱼精DNA之间的作用模式为插人作用.

We studied the mechanism of interaction and binding constant between Eu （Ⅲ） complex with methaerylic acid-8-hydroxyquinoline （Eu （MA）2 （hq）） and herring sperm DNA by using spectroscopic methods, viscosity and thermal denaturation method of DNA. Results show that the absorption peak has obvious hypochromic effect, but red shift phenomenon of peak is not obvious after the complex adding herring sperm DNA. The complex can quench the fluorescence of neutral red-DNA system. The binding ratio of n（Eu（MA）2 （hq）） ： n（DNA） is 1, and the binding constants are K20 = 5. 91 × 103 L/mol, and K35 =7. 70 × 10a L/mol. The thermodynamic functions between complex and herring sperm DNA are △r Hme=1. 34×103 J/tool, △r Gme=-2. 12×104 J/mol, and ×r Sme=76.41 J/（mol· K）. The relative viscosity and melting point of herring sperm DNA are increased with the addition of complex, and the interaction mode of the Eu（MA）2 （hq） with herring sperm DNA belongs to intercalation.