Atomic-scale investigation of the interaction between coniferyl alcohol and laccase for lignin degradation using molecular dynamics simulations and spectroscopy

The interaction between coniferyl alcohol (CA) and laccase (LAC) was investigated using molecular dynamics (MD) simulations and spectral experiments. The mode of interaction between CA and LAC was established by MD simulations. The micro-environmental changes, stability and rigidity of the LAC-CA system were assessed by relevant parameters. These parameters include root mean square deviation (RMSD), root mean square fluctuation (RMSF) and radius of gyration (Rg). The calculated binding free energy (ΔGbinding= −19.99 kcal·mol.−1), the van der waals (VDW) contribution (ΔGvdw=−23.99 kcal·mol−1) and the electrostatic energy (ΔGele=−23.09 kcal·mol−1) of LAC-CA system demonstrated that the interaction of LAC-CA was a spontaneous process and the main interaction forces were van der Waal's and electrostatic forces. The values of ΔGvdw and ΔGele were negative, which demonstrated that VDW interactions and electrostatic interactions were favorable for the binding of CA and LAC. The binding constants, thermodynamic parameters, molecular force types and binding distances confirmed the interaction between CA and LAC and further verified the rationality of the theoretical model by spectral experiments. The MD simulations and experimental approaches provide clues for the discovery of new mediators and useful references for the mechanism of microbial degradation of lignin and industrialization of lignocellulose.