农药异丙威与小牛胸腺DNA的作用研究

在生理酸度条件下,采用紫外光谱和荧光光谱法研究异丙威与小牛胸腺DNA的作用表明:DNA对异丙威的荧光有明显的猝灭作用,属于静态猝灭方式;K4[Fe(CN)6]猝灭试验发现DNA对异丙威有明显的保护作用,离子强度的改变对异丙威和异丙威-DNA体系的荧光均无明显影响;异丙威的加入使DNA的熔点升高,并且异丙威能够竞争置换EB与DNA的结合位点。上述实验也表明,异丙威以嵌插方式作用于DNA的结合位点,有可能通过形成DNA加合物的形式造成DNA损伤,从而最终导致基因突变。

Studies on the Interaction of Aminocarb with Calf Thymus DNA

The interaction between isoprocarb and calf thymus ct-DNA in physiological buffer (pH 7.4) was studied by UV absorption and fluorescence spectroscopy. The fluorescence quenching studies showed a regular decrease in the fluorescence intensity after addition of ct-DNA by a static quenching mode. K_4[Fe(CN)_6] quenching experiment revealed obvious protection of ct-DNA to isoprocarb, and the fluorescence intensity of isoprocarb and isoprocarb-DNA didn't significantly change with the change of ionic strength. The value of melting temperature of DNA increased in the presence of isoprocarb, and there was a strong competition for DNA binding between isoprocarb and ethidium bromide. Based on the above experimental results, it can be inferred that the binding mode of isoprocarb with DNA is intercalative binding, and that the isoprocarb can bind to base pairs of DNA to produce DNA adducts. Isoprocarb might bring the chemical trauma to DNA of the organisms and induce gene mutation through producing DNA adducts.