Exploration of binding mechanism of whey protein isolate and proanthocyanidin: Spectroscopic analysis and molecular dynamics simulation

[Display omitted] •Binding of whey protein isolate (WPI) to proanthocyanidin (PC) was near Tyr residue.•The binding of PC altered the conformation and surface hydrophobicity of WPI.•The dominant driving force of WPI binding to PC was hydrogen bond.•The microstructure of WPI-PC complex was irregular and had a small sheet structure.•PC and WPI remained a stable bound mainly through the energy contribution of LEU 39. The non-covalent whey protein isolate-proanthocyanidin (WPI-PC) complex was constructed and possessed superior anti-muscle attenuation activity in our previous study. While the non-covalent binding mechanism of WPI and PC remains unclear. The interaction mechanism of whey protein isolate (WPI) and proanthocyanidin (PC) was explored using multispectral analysis and molecular dynamics (MD) simulation. The results indicated that the non-covalent binding of PC and WPI led to fluorescence quenching, causing the conformational changes and microenvironment changes of WPI. The surface hydrophobicity of WPI-PC complex was reduced by 42.36 % compared with WPI (P