Insights into the binding mechanism of Monascus pigment with Holo-ovotransferrin by multispectral and molecular dynamics simulation.

The widespread application of Monascus pigment (MP) is limited by its poor stability. To address this, a Holo-OVT/MP complex was constructed to enhance MP stability. The binding mechanism was investigated using multispectral analysis and computational simulations. Spectroscopic studies confirmed the specific binding of MP to Holo-OVT, inducing static fluorescence quenching of the protein. The thermodynamic parameters derived from Trp/Tyr fluorescence spectroscopy indicated spontaneous interactions. The lowest binding energy for the Holo-OVT/ MP complex was calculated as -6.49 kJ/mol. Hydrogen bonding, hydrophobic interactions, and van der Waals forces were the primary driving forces for the formation and stability of the complex. CD spectroscopy showed a 5.5 % decrease in α-helix and a 29.7 % increase in β-sheet content in Holo-OVT. MD results further demonstrated that MP binding induced conformational changes in Holo-OVT's secondary and tertiary structures. These findings provide a mechanistic basis for developing stable MP formulations applicable to food processing and storage.