Interaction behavior between bisphenol AP and pepsin: Insights from density functional theory, and spectroscopic and molecular dynamic simulation

Overuse of polymer materials has caused increasing direct human exposure to bisphenol AP (BPAP). Through the contaminated environment and food chains, adverse effects BPAP on humans plants induce growing concerns. In this study, pepsin structure changes were exhaustively investigated by multi-spectral methods. Under mimic physiological conditions, a gradient intrinsic fluorescence quenching inducing microenvironmental surrounding residues with endogenous in pepsin. During ground-state complex formation, senior structures altered addition. Fourier transform infrared spectroscopy circular dichroism showed that secondary tertiary changed after addition BPAP. Thermodynamic parameter analysis demonstrated binding was spontaneous process mainly driven hydrophobic interaction van der Waals force. With as subject density functional theory experiments, energies highest occupied molecular orbital, lowest unoccupied electrostatic potential calculated evaluate electronic distribution Molecular docking experiments displayed specific pattern, hydrogen-bonding between one hydroxyl groups amino acids vital stabilizing BPAP−pepsin complex. The root mean square deviation, total hydrogen bonds statistic, Ramachandran map obtained dynamic simulations validated findings predicted rationality structure. This study provides an experimental theoretical basis for understanding mechanism pollution It also puts forward strategies strengthen safety achieve precise control environmental contaminants industry.