1. The mechanism of interaction between tri-para-cresyl phosphate and human serum protein: A multispectroscopic and in-silico study.
- Author
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Li SC, Xu H, Wang PF, Wang LM, Du YR, Guan YB, Han ZX, and Zhang QB
- Subjects
- Humans, Serum Albumin, Human chemistry, Serum Albumin, Human metabolism, Flame Retardants metabolism, Spectrophotometry, Ultraviolet, Binding Sites, Tritolyl Phosphates chemistry, Tritolyl Phosphates metabolism, Serum Albumin chemistry, Serum Albumin metabolism, Hydrogen Bonding, Molecular Docking Simulation, Molecular Dynamics Simulation, Spectrometry, Fluorescence, Thermodynamics, Protein Binding
- Abstract
Organophosphate flame retardants (OPFRs) pose the significant risks to the environment and human health and have become a serious public health issue. Tricresyl phosphates (TCPs), a group of aryl OPFRs, exhibit neurotoxicity and endocrine disrupting toxicity. However, the binding mechanisms between TCPs and human serum albumin (HSA) remain unknown. In this study, through fluorescence and ultraviolet-visible (UV-vis) absorption spectroscopy, molecular docking and molecular dynamics (MD), tri-para-cresyl phosphate (TpCP) was selected to explore potential interactions between HSA and TCPs. The results of the fluorescence spectroscopy demonstrated that a decrease in the fluorescence intensity of HSA and a blue shift were observed with the increasing concentrations of TpCP. The binding constant (K
a ) was 2.575 × 104 L/mol, 4.701 × 104 L/mol, 5.684 × 104 L/mol and 9.482 × 104 L/mol at 293 K, 298 K, 303 K, and 310 K, respectively. The fluorescence process between HSA and TpCP involved a mix of static and dynamic quenching mechanism. The gibbs free energy (ΔG0 ) of HSA-TpCP system was -24.452 kJ/mol, -25.907 kJ/mol, -27.363 kJ/mol, and - 29.401 kJ/mol at 293 K, 298 K, 303 K, and 310 K, respectively, suggesting that the HSA-TpCP reaction was spontaneous. The enthalpy change (ΔH0 ) and thermodynamic entropy change (ΔS0 ) of the HSA-TpCP system were 60.83 kJ/mol and 291.08 J/(mol·>k), respectively, indicating that hydrophobic force was the major driving force in the HSA-TpCP complex. Furthermore, multispectral analysis also revealed that TpCP could alter the microenvironment of tryptophan residue and the secondary structure of HSA and bind with the active site I of HSA. Molecular docking and MD simulations confirmed that TpCP could spontaneously form a stable complex with HSA, which was consistent with the fluorescence experimental results. This study provides novel insights into the mechanisms of underlying the transportation and distribution of OPFRs in humans., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
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