Application of spectroscopic techniques combined with molecular docking for the study of the interactions between bovine lactoferrin, 20-carbon unsaturated fatty acid, and rutin

Abstract The interaction mechanism of lactoferrin (LF) with arachidonic acid (AA)/eicosapentaenoic acid (EPA) and rutin (RU) was investigated by spectroscopic method and molecular docking technique. The investigation revealed that LF and AA/EPA bind to form a stable complex. The quenching mechanism of RU on LF and the LF-fatty acid complex was identified as static quenching. The thermodynamic analysis further substantiated that the bonding process was characterised by an endothermic nature and driven by entropy, with hydrophobic interaction serving as the predominant driving force. Synchronous fluorescence analysis revealed a closer proximity of the interaction site to the tryptophan residue, which was further confirmed by three-dimensional fluorescence and 8-Amino-1-naphthalenesulfonic acid fluorescence assays. The molecular docking study revealed the binding sites of LF with unsaturated fatty acids and RU. The present study elucidated the microscale interactions between LF and bioactive compounds, thereby providing a theoretical foundation for the creation of innovative functional foods and supplements.