Competitive binding and characteristic properties of pea 7S protein with three phenolic compounds: Implications for digestion and intestinal transport

The delivery of phenols by proteins as carriers is a current research hotspot, but single phenol can no longer sufficient to meet people's health needs. In this study, a protein-phenol triligand complex of curcumin, resveratrol, caffeic acid and pea 7S protein was constructed. Fluorescence spectroscopy confirmed that quenching constants (Ksv) of resveratrol, curcumin and caffeic acid binding to protein were 2.73 × 10⁴ M⁻¹, 3.35 × 10⁴ M⁻¹and 3.38 × 10⁴ M⁻¹, respectively, indicating that caffeic acid has the strongest binding affinity. Fluorescence spectroscopy and molecular docking techniques revealed binding regions and competitive binding processes. In vitro simulation digestion experiments indicated that the binding of phenols increased digestibility of proteins from 26.51% to 29.54%. After transport by Caco-2 cells, the release rates of resveratrol, curcumin and caffeine were 68.52%, 70.65% and 36.59% respectively, indicating that 7S protein might protect the absorption of phenols. These findings highlight the potential of 7S protein to deliver multiple phenols.