Abstract

In this study, the interacting characteristics of dibenzo[a,h]anthracene (DBA) with free DNA in vitro were investigated through multiple conventional spectroscopic techniques. UV–vis absorption spectroscopy was used to initially explore whether there was an interaction between DBA and DNA. Fluorescence spectroscopy was exploited to explore the binding characteristics and binding force between DBA and DNA. Circular dichroism (CD) spectra and DNA thermal denaturation measurement are utilized to further explore the binding mode between DBA and DNA. Magnetic bead separation technique coupled with fluorescence microscopic observation visually demonstrated the binding between DBA and DNA, and the residual amount of DBA was measured by fluorescence intensity. The results show that DBA can bind to DNA in vitro through intercalation mode. In the process of forming DBA–DNA complex, hydrogen bond and van der Waals force play a major role. The binding constant (K _A) and binding sites (n) are 2.039 × 10⁵ L/mol and 1.0451 at 25 °C, respectively. Moreover, DNA can be used to capture DBA in the solution based on DBA–DNA intercalation, and its removal efficiency is 98.24%. This work can provide new insights for the establishment of a novel polycyclic aromatic hydrocarbons (PAHs) elimination method based on PAHs–DNA intercalation.

摘要

在这项研究中，二苯并[ a，h ]蒽（DBA）与游离DNA的体外相互作用特征通过多种常规光谱技术进行了研究。紫外可见吸收光谱法最初用于探索DBA和DNA之间是否存在相互作用。利用荧光光谱法研究了DBA与DNA的结合特性和结合力。圆二色性（CD）光谱和DNA热变性测量被用来进一步探索DBA和DNA之间的结合模式。磁珠分离技术结合荧光显微镜观察，目测证明了DBA与DNA的结合，并通过荧光强度测量了DBA的残留量。结果表明DBA可以在体外与DNA结合通过插入模式。在形成DBA-DNA复合物的过程中，氢键和范德华力起主要作用。在25℃下的结合常数（K _A）和结合位点（n）分别为2.039×10 ⁵ L / mol和1.0451。此外，基于DBA–DNA插入，​​DNA可用于捕获溶液中的DBA，其去除效率为98.24％。这项工作可以为基于PAHs-DNA嵌入的新型多环芳烃（PAHs）消除方法的建立提供新的见识。