Interacting mechanism of benzo(a)pyrene with free DNA in vitro

• Published in: International journal of biological macromolecules Vol. 167; pp. 854 - 861
• Main Authors: Xiong, Yining, Li, Junsheng, Huang, Guoxia, Yan, Liujuan, Ma, Ji
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.01.2021
• Subjects: Benzo(a)pyrene; Benzo(a)pyrene - analysis; Benzo(a)pyrene - chemistry; Carbon - chemistry; Chemical Phenomena; Circular Dichroism; DNA; DNA - chemistry; Environmental Pollutants - chemistry; Hydrogen Bonding; Interacting mode; Magnetic bead; Molecular Docking Simulation; Molecular Dynamics Simulation; Nucleic Acid Conformation; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - chemistry; Spectroscopic method; Spectrum Analysis; Thermodynamics; Transition Temperature; Magnetic bead; Interacting mode; Benzo(a)pyrene; DNA; Spectroscopic method
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.11.042

Polycyclic aromatic hydrocarbons are environmental pollutants with strong carcinogenicity, indirect teratogenicity, and mutagenicity. This study explored the interaction mechanism of benzo(a)pyrene with free DNA in vitro by using various analytical methods. UV–vis spectra showed that benzo(a)pyrene and DNA formed a new benzo(a)pyrene–DNA complex. The thermal melting temperature of DNA increased by 12.7 °C, showing that the intercalation of benzo(a)pyrene into DNA could promote the stability of the DNA double helix structure. The intercalation of benzo(a)pyrene with DNA in vitro was further confirmed by fluorescence microscopy with magnetic beads. Fluorescence spectra showed that the interaction between DNA and benzo(a)pyrene decreased the fluorescence intensity of benzo(a)pyrene, and the maximum quenching rate was 27.89%. The quenching mode of benzo(a)pyrene was static quenching. Thermodynamic data showed that the main driving forces were van der Waals forces and hydrogen bonds, and the reaction was spontaneous. The results of this study provided a novel insight for the establishment of polycyclic aromatic hydrocarbon capture and elimination through polycyclic aromatic hydrocarbon–DNA intercalation.