Investigation of the interaction between (−)‐epigallocatechin‐3‐gallate with trypsin and α‐chymotrypsin

Summary Tea polyphenol ( TP ) inhibits digestive enzymes and reduces food digestibility. To explore the interaction between TP with digestive enzymes, bindings of ‐epigallocatechin‐3‐gallate ( EGCG ) to trypsin and α‐chymotrypsin were studied in detail using fluorescence, resonance light‐scattering, circular dichroism, fourier transform infrared spectroscopy methods and protein‐ligand docking. The binding parameters were calculated according to S tern– V olmer equation, and the thermodynamic parameters were determined by the van't H off equation. The results indicated that EGCG was capable of binding trypsin and α‐chymotrypsin with high affinity, resulting in a change of native conformation of these enzymes. EGCG had a greater influence on the structure of α‐chymotrypsin than trypsin. This study can be used to explain the binding interaction mechanism between TP and digestive enzymes.