The Binding mechanism of anthocyanins from sour cherries (Prunus cerasus L) skins to bovine -lactoglobulin: A fluorescence and in silico-based approach

Fluorescence spectroscopy and computational methods were used to study the interaction between anthocyanins from sour cherries extract and bovine -lactoglobulin. The experimental tests indicated that the number of binding sites was lower than 1, suggesting weak binding of anthocyanins by -lactoglobulin, most probably as the result of the multitude of compounds present in the extract. Intrinsic and extrinsic fluorescence experiments have highlighted blue- and red-shifts in maximum emission. In agreement with the fluorescence spectroscopy findings, the in silico results suggested better affinity of the protein preliminary treated at high temperature for the anthocyanin. The molecular docking tests performed using the cyanidin 3-rutinoside as the ligand, one of the major components of anthocyanin extract indicated that the driving forces leading to complex formation mainly involve diamino and nonpolar neutral amino acids on the surface of the protein. The stability of the complex appeared to be mainly ensured by hydrophobic interactions and hydrogen bonds.