Surface plasmon resonance, molecular docking, and molecular dynamics simulation studies of lysozyme interaction with...

Lysozyme (L_ZM) is an important enzyme in medicine and industry. Tannic acid (TA) is used in brewing, wine industry, and as a food flavor enhancer. In nutritional and food science, L_ZM interacts with TA, notably in wine and saliva. This study aimed to investigate the binding interaction between L_ZM and TA using surface plasmon resonance, molecular docking, and molecular dynamics simulation. Chicken egg white lysozyme (CEWL_ZM) was applied as a model protein. Tri-N-acetylchitotriose (NAG₃), the known inhibitor of CEWL_ZM, was used in the redocking experiments to determine the precise binding location within the complex. The average binding energies obtained from docking NAG₃ and tannic acid to the target structure of CEWL_ZM were found to be -6.46 ± 0.05 kcal/mol and -7.52 ± 0.39 kcal/mol, respectively. The binding free energy of the CEWL_ZM-TA complex was then calculated as -27.61 kcal/mol by MMPBSA based on MD simulation trajectories. The observed interactions between the ligands and the lysozyme structure were mainly driven by hydrophobic, van der Waals, and H-bond interactions formed by the active site residues. MD simulations showed consistent and satisfactory binding distances between CEWL_ZM and TA throughout the analysis. SPR analysis was performed using 1X PBS buffer (pH 7.4) as coupling and running buffers, 30 μL/min as flow rate, and 2.5 mg/mL CEWL_ZM. Serial concentrations of TA (20-150 μM) were injected through immobilized CEWL_ZM, and the K value of CEWL_ZM-TA binding was obtained as 4.17 × 10^-5 M. This study could enhance existing literature and pave the way for future research in food science and oral biology.