Binding mechanism of Monascus pigment and ovalbumin: spectral analysis, molecular docking and molecular dynamics simulation

The interaction amid Monascus pigment (MP) and ovalbumin (OVA) was studied using multispectral and computer simulations. The fluorescence results demonstrated that MP could effectively quench the fluorescence emission of OVA. According to Stern-Volmer and the double logarithmic equation, the quenching reaction of MP to OVA was static quenching, which was brought on by the combination of two molecules to shape a complex. At 298 K, the conjunction constant K_a of MP and OVA was 1.045 2 × 10⁹ L/mol, and the count of conjunction sites n was 1.955 7. The thermodynamic constant of MP-OVA binding was counted according to Van’s Hoff equation, and the reaction belonged to the active process of reducing Gibbs free energy. The ultraviolet–visible (UV-Vis) absorption spectroscopy indicated an interaction between MP and OVA. The interaction force between MP and OVA and the steadiness of the conjunction were examined by using molecular docking and molecular dynamics simulation. The findings suggested that MP formed a complex with OVA via non-covalent binding, the formation and steadiness of the complex were promoted through hydrogen bonding, hydrophobic interaction, and Van der Waals force.