Formation of nanocomplexes comprising whey proteins and fucoxanthin: Characterization, spectroscopic analysis, and molecular docking

Fully elucidating the protein-ligand interaction mechanisms can help us better construct the nanocarrier to delivery fucoxanthin. Thus, in this study, the complexes comprising fucoxanthin and whey proteins were constructed and characterized, using bovine serum albumin (BSA), β-lactoglobulin (β-Lg), and α-lactoalbumin (α-La). The binding processes were also investigated using multi-spectroscopic methods and molecular docking. The results indicated that the skeletons of BSA/β-Lg/α-La were loosened and unfolded, and the protein aggregates were formed with a nano scale (<300 nm) in the presence of fucoxanthin. The number of binding sites was about equal to 1. The binding affinity in decreasing order was BSA, β-Lg, α-La. Based on thermodynamic investigations, all binding processes were spontaneous, and non-covalent interactions were the major driving forces for the formation of whey protein–fucoxanthin nanocomplexes. Docking results also indicated the contribution of van der Waals force, hydrogen bond and hydrophobic interaction when the nanocomplexes were formed, well agreeing with the thermodynamic analysis.