Binding of hydroxylated polybrominated diphenyl ethers with human serum albumin: Spectroscopic characterization and molecular modeling |
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| Authors: | Lulu Yang Wu Yang Zhiwei Wu Zhongsheng Yi |
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| Affiliation: | Guangxi Colleges and Universities Key Laboratory of Food Safety and Detection, Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, China |
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| Abstract: | Three hydroxylated polybrominated diphenyl ethers (OH‐PBDEs), 3‐OH‐BDE‐47, 5‐OH‐BDE‐47, and 6‐OH‐BDE‐47, were selected to investigate the interactions between OH‐PBDEs with human serum albumin (HSA) under physiological conditions. The observed fluorescence quenching can be attributed to the formation of complexes between HSA and OH‐PBDEs. The thermodynamic parameters at different temperatures indicate that the binding was caused by hydrophobic forces and hydrogen bonds. Molecular modeling and three‐dimensional fluorescence spectrum showed conformational and microenvironmental changes in HSA. Circular dichroism analysis showed that the addition of OH‐PBDEs changed the conformation of HSA with a minor reduction in α‐helix content and increase in β‐sheet content. Furthermore, binding distance r between the donor (HSA) and acceptor (three OH‐PBDEs) calculated using Förster's nonradiative energy transfer theory was <7 nm; therefore, the quenching mechanisms for the binding between HSA and OH‐PBDEs involve static quenching and energy transfer. Combined with molecular dynamics simulations, the binding free energies (ΔG bind ) were calculated using molecular mechanics/Poisson ? Boltzmann surface area method, and the crucial residues in HSA were identified. |
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| Keywords: | human serum albumin hydroxylated polybrominated diphenyl ethers molecular modeling three‐dimensional fluorescence |
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