Abstract:In order to explore the antioxidant effect and molecular mechanism of five active peptides derived from wheat protein, five active peptides [Leu-Tyr (LY), Pro-Tyr (PY), Tyr-Gln (YQ), Ala-Pro-Ser-Tyr (APSY), Arg-Gly-Gly-Tyr(RGGY)] were isolated and identified from wheat protein. Five antioxidant evaluation systems including DPPH free radical scavenging capacity, hydroxyl free radical scavenging capacity, oxygen free radical absorption capacity (ORAC value), reducing capacity and total antioxidant capacity (FRAP method) were used to investigate their antioxidant effects. The results showed that LY, PY, YQ, APSY and RGGY had good antioxidant activity in five evaluation systems, among which PY had the most prominent antioxidant activity, and the activity values were (88.90±2.25)%, (5 143.68±65.45) μmol Trolox/g, (55.64%±1.12)%, 0.27±0.02 and (0.68±0.01)mmol/L, respectively. The chemical structure of wheat protein-derived active peptides was simulated by quantum chemistry, and stable dominant conformation was obtained. The molecular energies were -2 792 298.02, -2 490 523.05, -2 831 549.24, -3 977 343.70 and -4 111 743.04 kJ/mol. The optimal docking configurations of five active peptides and DPPH were obtained by molecular docking technology. LY and RGGY bound to DPPH through hydrogen bonds and Π-cationic electrostatic interaction, PY bound to DPPH through Π-Π accumulation Π-cationic electrostatic interaction and Π-anionic electrostatic interaction, YQ bound to DPPH through Π-cationic electrostatic interaction and Π-qnionic electrostatic interaction, and APSY bound to DPPH through hydrogen bond, Π-Π accumulation, Π-cationic electrostatic interaction and Π-anionic electrostatic interaction.