Complexation of bovine lactoferrin with selected phenolic acids via non-covalent interactions: binding mechanism and altered functionality

ABSTRACT Non-covalent interactions of 4 selected phenolic acids, including gallic acid (GA), caffeic acid (CA), chlorogenic acid (CGA), and rosmarinic acid (RA) with lactoferrin (LF) were investigated. Compound combined with LF in the binding constant of CA > GA > RA > CGA, driven by van der Waals (vdW) and hydrogen bonding (H-bonds) for GA, and hydrophobic forces for others. Conformation of LF was impacted at secondary and ternary structure levels. Molecular docking indicated that GA and CA located in the same site near the iron of the C-lobe, while RA and CGA bound to the C2 and N-lobe, respectively. Significantly enhanced antioxidant activity of complexes was found compared with pure LF ( P < 0.05), as demonstrated by DPPH, ABTS, FRAP models. CA, CGA, and RA significantly decreased the ESI and improved foam ability of LF ( P < 0.05), and the effect of CA and RA was the most remarkable, respectively.