苯酚红与鲱鱼精DNA的相互作用

Interaction between Phenol Red and herring sperm DNA

在Tris-HCl(pH=7.40)缓冲溶液中,采用紫外-可见光谱法、荧光光谱法研究了苯酚红(PR)与鲱鱼精DNA的相互作用,表明PR与DNA之间存在静电作用,结合比为nPR∶nDNA=2∶1.同时测得PR与DNA的结合常数K20℃=5.96×104L.mol-1,热力学函数ΔrHm=-20.67 KJ.mol-1,ΔrSm=20.89 J.mol-1.K-1,ΔrGm=-26.78 KJ.mol-1;应用荧光探针法(以吖啶橙(AO)为荧光探针)和粘度法研究发现PR对DNA有部分嵌入作用.综上所述,PR与DNA之间为嵌入作用和静电作用的复合方式.

The interaction of phenol red （PR） with herring sperm DNA was confirmed by UV - Vis spectra and fluorescence spectra in the Tris - HC1 （ pH = 7.40 ） buffer solution. The results indicated that the electrostatic effects were existent between PR and DNA, with the binding ratio of nPR∶nDNA=2∶1, the binding constant of K20℃=5.96×104L.mol-1 The thermodynamic functions of the interaction were calculated： ΔrHm=-20.67 KJ.mol-1,ΔrSm=20.89 J.mol-1.K-1,ΔrGm=-26.78 KJ.mol-1 Furthermore, their interaction was also studied through fluorescence probe method （used acridine orange （AO） as a fluorescence probe） and viscosity method, the results showed that there was partly intercalation effects between PR and DNA. In summary, the binding mode of PR to DNA both included the intercalation and electrostatic effects.