Binding Characteristics of Dibenzo[a,h]Anthracene with DNA In Vitro: Investigated by Spectroscopic and Magnetic Bead Methods

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.