Polycyclic aromatic hydrocarbon (PAH)-DNA binding is an essential step in PAH-induced carcinogenesis. A large number of PAHs contain substituents, it is unclear whether functional groups will influence the PAH-DNA binding. Here, we investigated amino (-NH2) and hydroxy (-OH) substitution on pyrene-DNA binding. Because of the considerable effects of electrostatic surface potential (ESP), -NH2 substitution significantly facilitated binding by increasing the binding constant (log KA) from 4.14 L mol-1 to 12.31 L mol-1, while -OH substitution inhibited binding by reducing log KA to 3.68 L mol-1. Spectroscopy results revealed that pyrene and its derivatives were able to bind with thymine to induce DNA damage or double helix distortion. Quantum chemical calculations showed that -NH2 substitution induces hydrogen bond formation, thereby enhancing the binding of pyrene with DNA; moreover, binding force changes due to -OH substitution may not be an essential factor. All structural descriptors were not correlated with the quenching constant (KSV) or binding constant, indicating that changes in physicochemical properties shows no influence on pyrene-DNA binding. The results of this study will improve our understanding of the contribution of functional groups to PAH-DNA binding.

中文翻译：

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氨基和羟基取代影响pyr-DNA的结合。

多环芳烃（PAH）-DNA结合是PAH致癌作用中必不可少的步骤。大量的PAH含有取代基，目前尚不清楚官能团是否会影响PAH-DNA的结合。在这里，我们研究了pyr（DNA）结合上的氨基（-NH2）和羟基（-OH）取代。由于静电表面电势（ESP）的显着影响，-NH2取代通过将结合常数（log KA）从4.14 L mol-1增加到12.31 L mol-1显着促进了结合，而-OH取代通过降低log抑制了结合KA至3.68L mol-1。光谱结果表明，pyr及其衍生物能够与胸腺嘧啶结合，从而引起DNA损伤或双螺旋畸变。量子化学计算表明-NH2取代会诱导氢键形成，从而增强of与DNA的结合；此外，由于-OH取代引起的结合力变化可能不是必需因素。所有结构描述符与淬灭常数（KSV）或结合常数均不相关，表明理化性质的变化对shows-DNA结合没有影响。这项研究的结果将增进我们对官能团对PAH-DNA结合的贡献的理解。