Insights into the enzymatic degradation of DNA expedited by typical perfluoroalkyl acids  

作　　者：Chao Qin Run-Hao Zhang Zekai Li Hai-Ming Zhao Yan-Wen Li Nai-Xian Feng Hui Li Quan-Ying Cai Xiaojie Hu Yanzheng Gao Lei Xiang Ce-Hui Mo Baoshan Xing 

机构地区：[1]Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials,College of Life Science and Technology,Jinan University,Guangzhou 510632,China [2]Institute of Organic Contaminant Control and Soil Remediation,College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China [3]Stockbridge School of Agriculture,University of Massachusetts,Amherst,MA 01003,United States

出　　处：《Eco-Environment & Health》2023年第4期278-286,共9页生态环境与健康（英文）

基　　金：This work was funded by the National Natural Science Foundation of China(42030713,42107221,42177187);Fundamental Research Funds for the Cornell University(21622109);the Natural Science Foundation of Guangdong Province(2020A1515110535,2018A030310629).

摘　　要：Perfluoroalkyl acids(PFAAs)are considered forever chemicals,gaining increasing attention for their hazardous impacts.However,the ecological effects of PFAAs remain unclear.Environmental DNA(eDNA),as the environmental gene pool,is often collected for evaluating the ecotoxicological effects of pollutants.In this study,we found that all PFAAs investigated,including perfluorohexanoic acid,perfluorooctanoic acid,perfluorononanoic acid,and perfluorooctane sulfonate,even at low concentrations(0.02 and 0.05 mg/L),expedited the enzymatic degradation of DNA in a nonlinear dose–effect relationship,with DNA degradation fragment sizes being lower than 1,000 bp and 200 bp after 15 and 30 min of degradation,respectively.This phenomenon was attributed to the binding interaction between PFAAs and AT bases in DNA via groove binding.van der Waals force(especially dispersion force)and hydrogen bonding are the main binding forces.DNA binding with PFAAs led to decreased base stacking and right-handed helicity,resulting in loose DNA structure exposing more digestion sites for degrading enzymes,and accelerating the enzymatic degradation of DNA.The global ecological risk evaluation results indicated that PFAA contamination could cause medium and high molecular ecological risk in 497 samples from 11 contamination-hot countries(such as the USA,Canada,and China).The findings of this study show new insights into the influence of PFAAs on the environmental fates of biomacromolecules and reveal the hidden molecular ecological effects of PFAAs in the environment.

关 键 词：DNA Enzymatic degradation Emerging organic pollutants Perfluoroalkyl acids Ecological effects 

分 类 号：X171[环境科学与工程—环境科学] X5