Dimethyl phthalate (DMP), a typical phthalic acid ester, is widespread in the environment and causes extensive concern due to its adverse effects on human health. To understand the genotoxicity of DMP at molecular level, the toxic interaction of DMP with herring sperm (hs) deoxyribonucleic acid (DNA; hs-DNA) was investigated in vitro under simulated physiological conditions using multi-spectroscopic techniques and a molecular modeling method. The results of Ultraviolet-Visible absorption spectroscopy, fluorescence emission spectroscopy, and circular dichroism spectra indicated that DMP interacts with hs-DNA in a groove-binding mode that changes the double helical structure of DNA. The binding constant and the number of binding sites calculated from the fluorescence quenching data were 565.718 L mol(-1) and 0.7872, respectively. A molecular modeling study revealed that DMP tends to bind with DNA in the A-T-rich regions of minor groove and that hydrogen bonding and van der Waals forces play main roles in the interaction. This research can help to elucidate the mechanism of DMP toxicity in vivo.

中文翻译：

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在分子水平上研究邻苯二甲酸二甲酯与鲱鱼精子DNA的作用机理。

邻苯二甲酸二甲酯（DMP），一种典型的邻苯二甲酸酯，在环境中广泛存在，由于其对人体健康的不利影响而引起广泛关注。为了了解DMP在分子水平上的遗传毒性，在体外模拟生理条件下，使用多光谱技术和分子建模方法研究了DMP与鲱鱼精子（hs）脱氧核糖核酸（DNA; hs-DNA）的毒性相互作用。紫外-可见吸收光谱，荧光发射光谱和圆二色性光谱的结果表明，DMP与hs-DNA以凹槽结合模式相互作用，从而改变了DNA的双螺旋结构。根据荧光猝灭数据计算的结合常数和结合位点数分别为565.718 L mol（-1）和0.7872。分子模型研究表明，DMP倾向于与AT富集的小沟区域中的DNA结合，并且氢键和范德华力在相互作用中起主要作用。这项研究可以帮助阐明体内DMP毒性的机制。