Comparing the binding interaction between β-lactoglobulin and flavonoids with different structure by...

Area of Science:

• Food Chemistry
• Biochemistry
• Molecular Interactions

Background:

• Flavonoids are plant compounds with potential health benefits.
• Beta-lactoglobulin (β-LG) is a major whey protein in milk.
• Understanding flavonoid-protein interactions is crucial for food applications.

Purpose of the Study:

• To investigate the interaction mechanisms between four flavonoids (apigenin, naringenin, kaempferol, genistein) and β-LG.
• To determine how structural modifications of flavonoids affect their binding affinity and interaction forces with β-LG.
• To explore the impact of flavonoid binding on β-LG conformation and surface hydrophobicity.

Main Methods:

• Multi-spectroscopy analysis (Circular Dichroism, fluorescence spectroscopy).
• Molecular docking simulations.
• Systematic selection of four flavonoids with varying structures.

Main Results:

• Hydrogenation of the C2C3 double bond in apigenin significantly weakened its affinity for β-LG.
• Apigenin and naringenin primarily interacted with β-LG via van der Waals forces and hydrogen bonds.
• Genistein and kaempferol interacted with β-LG mainly through hydrophobic interactions.
• Flavonoid binding caused β-LG conformation to loosen and reduced its surface hydrophobicity.
• Molecular docking revealed interactions with specific amino acid residues on β-LG's outer surface.

Conclusions:

• Flavonoid structure critically influences binding affinity and interaction modes with β-LG.
• Flavonoid-β-LG interactions alter protein structure, potentially affecting functional properties.
• Findings offer insights for incorporating flavonoids into dairy products.