Research of carrying mechanism between β-lactoglobulin and linoleic acid: Effects on protein structure and oxidative stability of linoleic acid

Spectroscopic techniques and molecular docking were employed to explore the binding mechanism and structural characteristics of β-lactoglobulin (β-lg) with linoleic acid. The research revealed that the interaction between β-lg and linoleic acid was primarily governed by static quenching. The attachment of linoleic acid to β-lg happened naturally via hydrophobic forces. The interaction between β-lg and linoleic acid had minimal impact on the area surrounding the tryptophan and tyrosine residues in β-lg, and it does not notably change the secondary structure of β-lg. Results of molecular docking and molecular dynamics indicated that linoleic acid binds mainly to the hydrophobic cavity inside β-lg, closer to the tryptophan residues.At the same time the stability of the proteins in the complex was significantly improved compared to the free β-lg. The stability against oxidation and the shelf life of the β-lg/linoleic acid complex were evaluated as well. Compared to free linoleic acid, the complex exhibited lower peroxide and anisidine values, suggesting that its formation with β-lg reduced the creation of primary oxidation products.