Investigation on dynamic interaction between cellulase and silicon nitride nanostructure at atomic level

Area of Science:

• Biomaterials Science
• Computational Chemistry
• Enzyme Engineering

Background:

• Silicon nitride (Si3N4, SiN) nanomaterials exhibit excellent biocompatibility, driving interest in biological and medical applications.
• Limited research exists on the specific interactions between SiN and enzymes, particularly cellulase.

Purpose of the Study:

• To investigate the atomic-level interaction mechanisms between cellulase and SiN nanostructures (nanolayer and nanopore).
• To elucidate how SiN affects cellulase structure, stability, and substrate binding affinity.
• To understand the relationship between SiN nanopore dimensions and enzyme translocation energy barriers.

Main Methods:

• Molecular dynamics (MD) simulations were employed to model the interactions.
• Umbrella sampling (US) approach was used for energetic calculations.
• Analysis focused on structural stability, active site residues, binding free energy, and energy barriers.

Main Results:

• Cellulase effectively adsorbs onto SiN nanolayers, enhancing its structural stability, including the active site.
• Enzyme adsorption strengthens the binding affinity between cellulase and its substrate, indicated by decreased binding free energy.
• A strong linear correlation was observed between SiN nanopore diameter and the energy barrier for cellulase passage.

Conclusions:

• SiN nanostructures significantly influence cellulase behavior, promoting adsorption and stabilizing its structure.
• The findings provide crucial insights into enzyme-nanomaterial interactions, relevant for enzyme immobilization and nanomaterial design.
• This study deepens the understanding of enzyme action mechanisms in the presence of nanomaterials.