Photophysical properties and dynamics simulation of the interaction between human serum albumin and hydroxy polybrominated diphenyl ether

Abstract

The absorption, distribution and metabolism of various ligands in organisms are particularly important for understanding biological systems and processes. Herein, this work presents the detail in the interaction between 3-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether and human serum albumin. Small molecule of ligand cause the endogenous fluorescence of human serum albumin to be quenched, and the quenching mechanism includes static quenching, dynamic quenching and non-radiative energy transfer. Synchronous fluorescence and site competition experiments demonstrate that 3-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether has one binding site with human serum albumin (site I). In addition, similar conclusions are obtained from the molecular docking experiment. Molecular dynamics confirms that human serum albumin bound with 3-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether has more compact structure and increased hydrophobicity. Circular dichroism spectra exhibites that the α-helix of the complex are reduced by 21.2% relative to free human serum albumin. More importantly, thermodynamic reveals that hydrophobic interaction is identified as the primary driving force for the formation of the complex. This work provides valuable reference for the mechanism of interaction between organic pollutants and human serum albumin by multiple-spectra and theoretical simulation.