Erratum to: Study on the binding interaction between perfluoroalkyl acids and DNA

Abstract

Abstract Perfluoroalkyl acids (PFAAs) are carcinogens,and elucidating their DNA binding properties is crucial forunderstanding PFAA genotoxicity. We have investigated thebinding mode and affinity of five PFAAs to seven DNAmolecules using fluorescence displacement and moleculardockinganalysis. DNA conformational changes uponPFAAbinding were also examined by circular dichroism (CD).The data revealed that DNA intercalation was the dominantinteraction mode of the PFAAs; however, these moleculesalso bound to grooves. The dissociation constants for thePFAAs ranged between 0.11 and 1,217.14 μM, and between3.46 and 2,141.21 μM for DNA intercalation and groovebinding, respectively. PFAAs that contain longer carbonchains had stronger DNA intercalation affinities. Bindingto DNA was stronger for perfluoroalkyl sulfonates than forperfluorcarboxyl acids that contain the same number ofcarbons. This observation is postulated to arise from thepresenceofmorefluorineandoxygenatomsinperfluoroalkylsulfonates acting as hydrogen bond donors that facilitatestronger DNA intercalation. The binding of the PFAAs toDNA showed some CT-DNA sequence selectivity. Moleculardocking analysis confirmed the DNA binding mode andaffinities of the PFAAs. CD analysis revealed that thePFAAs weakened DNA base stacking and loosened DNAhelicity.Thepresentstudyhasimprovedourunderstandingofthe formation of PFAA–DNA adducts.Keywords Perfluoroalkylacids .DNAbinding .Intercalation .Minorgroovebinding .DNAconformationalchange .DNAsequenceselectivityIntroductionPerfluoroalkyl acids (PFAAs) have been produced and usedfor over 50 years. Because of their specific physical andchemical properties, chemical and thermal inertness, lowsurface energy, and special surface-active properties,PFAAs have applications in numerous industrial and con-sumer products, ranging from carpet protection to fire-fighting foams (Lehmler 2005; Martin et al. 2004). PFAAspersist ubiquitously in the environment, resisting hydrolysis,photolysis, and biodegradation because of the high energyof the carbon–fluorine bond (Hekster et al. 2003; Martin etal. 2004; Quinete et al. 2010). Although the toxicologicaleffects of these chemicals are still under investigation, manystudieshavereportedontheirdevelopmentalandreproductivetoxicity, neurotoxicity, immunotoxicity, and carcinogenicityinanimalsbothinvivoandinvitro(Heksteretal.2003;Lauetal. 2004; Slotkin et al. 2008). PFAAs can cause peroxisomalproliferation, mitochondrial dysfunction, disturbance of fattyacid metabolism, hepatocellular hypertrophy, changes in