title: Systematic investigation of the toxic mechanism of PFOA and PFOS on bovine serum albumin by spectroscopic and molecular modeling.
abstract: Perfluorinated compounds (PFCs), an emerging class of globally environmental contaminations, pose a great threat to humans with wide exposure from food and other potential sources. The effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on bovine serum albumin (BSA) under normal physiological conditions were characterized by fluorescence, UV-Vis absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. The fluorescence study suggested that the fluorescence quenching of BSA by PFCs was a static procedure forming a PFCs-BSA complex. The negative values of enthalpy change (ΔH) and entropy change (ΔS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of PFCs to BSA. The displacement experiments of site markers and molecular docking revealed that the binding of PFOA to BSA took place in sub-domain IIA (Sudlow site I) whereas PFOS was mainly located in the sub-domain IIIA (Sudlow site II) and partially bound into site I. Furthermore, the results of UV-Vis and FT-IR spectra demonstrated that the microenvironment and the secondary structure of BSA were changed in the presence of PFCs. These results indicated that PFCs indeed impact the conformation of BSA and PFOS was more toxic than PFOA, which were supported by theoretical molecular modeling methods.
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China. Electronic address: chenhuilun@gmail.com.
authors.forename: Huilun
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China.
authors.forename: Pengzhen
authors.initials: P
authors.lastname: He
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China.
authors.forename: Honghao
authors.initials: H
authors.lastname: Rao
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China. Electronic address: yaojun@ustb.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
mesh_terms: D017738:Alkanesulfonic Acids / Q000633:toxicity*; D000818:Animals; D002210:Caprylates / Q000633:toxicity*; D002417:Cattle; D005466:Fluorocarbons / Q000633:toxicity*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D012710:Serum Albumin, Bovine; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid
keywords: Fluorescence quenching; Molecular docking; Perfluorooctane sulfonate (PFOS); Perfluorooctanoic acid (PFOA); Serum albumin; Thermodynamics