Study on Spectral Method and Computational Simulation of Chlorinated Bisphenol Compound and Thyroxine‐Binding Globulin

Abstract

AbstractBisphenol A (BPA) and chlorinated derivatives (Chlorinated bisphenol A, Cl‐BPA) are recognized as chemicals that destroy the endocrine system and widely exist in the environment. Because theirs structure is similar to thyroxin, it can compete after binding with Cl‐BPA were studied by fluorescence spectroscopy, Förster resonance energy transfer, Fourier transform infrared spectroscopy, molecular docking and quantum chemistry. The results of fluorescence experiments show that Cl‐BPA can quench the fluorescence of TBG by static quenching and non‐radiative energy transfer. The number of binding sites (n) of Cl‐BPA‐TBG complex is about 1, and the binding constant (Ka) is greater than 1.00×106 L⋅mol−1. Combined with thermodynamic parameter analysis and molecular docking analysis, Cl‐BPA can bind to TBG through hydrogen bonding and hydrophobicity. Quantum chemical analysis further confirmed that the oxygen atoms in Cl‐BPA compounds are easy to form hydrogen bonding forces with NH and OH in TBG. Further molecular dynamics simulation analysis showed that the protein structure changed after Cl‐BPA combined with TBG. In this study, we have a deep understanding of the interaction mechanism between Cl‐BPA and thyroid protein through various spectral experiments and computer simulation methods.