农药西玛津与小牛胸腺DNA的相互作用

在生理条件(pH 7.4)下,以吖啶橙(AO)为荧光探针,运用荧光光谱、紫外-可见光谱、圆二光谱(CD)和傅里叶转换红外光谱(FT-IR)并结合熔点、粘度及盐效应实验,研究了西玛津与小牛胸腺DNA的相互作用。结果显示,随着溶液中西玛津的浓度增大,DNA-AO复合物的荧光逐渐被猝灭,表明西玛津与AO发生了部分置换作用,而且西玛津的存在使得DNA的熔点和粘度增大,由此推断西玛津与DNA发生嵌插结合。此外,FT-IR光谱分析和盐效应结果表明西玛津与DNA还存在静电结合。计算出的热力学参数表明,疏水作用力是西玛津与DNA结合反应的主要驱动力。

Studies on the interaction of simazine with calf thymus DNA

The interaction between simazine and calf thymus DNA in a pH 7.4 Tris-HCl buffer was investigated with the use of acridine orange(AO) dye as a fluorescent probe by fluorescence,UV-vis absorption,circular dichroism(CD),and Fourier transform infrared(FT-IR) spectroscopy,as well as DNA melting studies,viscosity measurements and salt effect.It can be concluded that simazine molecules could intercalate into the base pairs of DNA as evidenced by slgnificant fluoresce ce quenching of the DNA-AO complex with the binding of simazine to DNA by substituting for AO in the DNA-AO complex,and increase in melting temperature and relative viscosity of DNA.Furthermore,the FT-IR spectroscopy and salt effect demonstrated that there exists electrostatic attraction between simazine and DNA simultaneously.The thermodynamic parameters suggested that the binding of simazine to DNA was driven mainly by hydrophobic interactions.