Antioxidant peptides from lupin hydrolysates identified by integrated peptidomic analysis, molecular docking and in vitro assays

Oxidative stress, associated with cardiovascular, neurodegenerative, and cancer-related disorders, may be mitigated by dietary intake of plant-derived antioxidants. In this study, lupin protein hydrolysates were generated using Proteinase K, Papain, and Biopeptidase. HLPI-3 showed the highest antioxidant activity in vitro. A total of 980 peptides with significant differences among enzymatic treatments were identified. Additionally, correlation analysis with antioxidant activity pointed out 36 peptides mainly from Hsp90, conglutin beta, and legumin-like proteins as the most likely contributors to antioxidant activity. Within these, bioinformatic predictions of peptide antioxidant capacity indicated 29 ranked highly (Pre-Score > 0.99) and seven top candidates were prioritized. Docking analysis against myeloperoxidase highlighted four peptides (GQNPLFPR, FLVPPPQS, FLVPPPQSQL, EKLPGGCGGQDH) with strong binding affinities (-8.5 to -9.9 kcal·mol^-1). These results demonstrate that integrating experimental screening with bioinformatic analysis provided a robust strategy for identifying promising antioxidant peptides from lupin proteins.