The Interaction Between Acacetin and Pepsin: A Studied by Multi-Spectral Method and Molecular Docking Simulation

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Flavonoids are plant compounds with potential therapeutic properties.
• Pepsin is a key digestive enzyme.
• Understanding flavonoid-protein interactions is crucial for drug discovery and food science.

Purpose of the Study:

• To investigate the binding mechanism between acacetin and pepsin.
• To elucidate the structural changes in pepsin upon acacetin binding.
• To provide insights into flavonoid-protein interactions for potential applications.

Main Methods:

• Multispectral techniques including fluorescence quenching, UV-visible, synchronous, 3D fluorescence, FT-IR, and circular dichroism spectroscopy.
• Förster Resonance Energy Transfer (FRET) calculations.
• Molecular docking simulations.

Main Results:

• Acacetin binds to pepsin with a high affinity (10^6 L mol^-1) via a static quenching mechanism.
• Hydrogen bonding and van der Waals forces are the primary driving forces for binding.
• Acacetin binding induces conformational changes in pepsin, affecting its aromatic residues and secondary structure (notably β-sheet content).
• Molecular docking confirms acacetin's stable binding near the pepsin active site.

Conclusions:

• Acacetin forms a specific, spontaneous complex with pepsin.
• The interaction involves close-range forces and leads to significant structural alterations in pepsin.
• This research offers valuable data for flavonoid-protein interaction studies, ligand design, and applications in the food and pharmaceutical industries.