Xanthine Oxidase Inhibitory Peptides from Sesame 11S Globulin Target the FAD Domain: Kinetics, Molecular Dynamics, and Validation in a Zebrafish Hyperuricemia Model.

Abstract

Food-derived bioactive peptides are promising alternatives to conventional xanthine oxidase (XO) inhibitors, yet individual XO inhibitory peptides from sesame protein remain uncharacterized. Here, sesame and peanut protein isolates were screened with four proteases; the trypsin hydrolyzate of sesame (TSH, 120 min) showed the highest XO inhibition (47.16%). Eight 11S globulin peptides were identified by nanoUHPLC-ESI-Q-TOF MS/MS. QGDIVAIPSGAAHW (IC50 = 467.2 μM) and AFYLAGGVPR (IC50 = 536.1 μM) exhibited mixed-type inhibition (α > 1). Molecular docking against two XO crystal structures (3NVY, 3NRZ) consistently favored the FAD domain, and 500 ns molecular dynamics simulations with MM-GBSA analysis provided convergent support (ΔG = -160 to -317 kJ mol-1). In a zebrafish hyperuricemia model, TSH reduced uric acid and XO activity while upregulating purine salvage (hprt1) and urate transport (oat1) genes. These findings support sesame-derived peptides as functional food candidates with preferential association with the XO FAD domain.