Abstract：The interaction between fenvalerate and calf thymus DNA at pH 7.4 in Tris-HCl buffer was investigated by fluorescence,UV-vis absorption,and circular dichroism(CD) spectroscopy,as well as viscosity measurements and DNA melting techniques.It was found that fenvalerate molecules could intercalate into the base pairs of DNA,evidenced by hyperchromicity in UV-vis absorption with the increasing concentration of the fenvalerate,and the decrease in iodide quenching effect,CD spectral constringency,and the significant increase in the relative viscosity and denaturation temperature of DNA.The intercalation binding of fenvalerate to DNA resulted in the damage of base stacking and the decrease of right-handedness of DNA.Moreover,the association constants were obtained from the fluorescence quenching data at three different temperatures.The thermodynamic parameters enthalpy change(ΔH) and the entropy change(ΔS) were calculated to be 78.63 kJ·mol-1 and 359.5 J·mol-1·K-1 respectively from the Van’t Hoff equation,which suggested that hydrophobic interaction was the main driving force in the binding of fenvalerate to DNA.
2012, Vol. 36 
