Multidimensional study of <scp>DPP</scp> ‐ <scp>IV</scp> inhibitory peptides from phycocyanin: Screening, identification, inhibitory mechanism, hypoglycemic activity <i>in vivo</i> and cellular transportation

BACKGROUND: Dipeptidyl peptidase IV (DPP-IV) inhibitors are well known medication for type 2 diabetes mellitus. The present study aimed to prepare and screen DPP-IV inhibitory peptides from phycocyanin (PC) and investigate their inhibition types and cellular transportation mechanism. RESULTS: , respectively, were separated and characterized from the < 3.0 kDa fraction of PC hydrolysates using affinity ultrafiltration and molecular docking techniques. Both peptides exhibited a mixed inhibition pattern against DPP-IV, and bound to the active site of DPP-IV mainly through hydrogen bonds and hydrophobic interactions. IASY showed better biocompatibility and absorption transport rate than IAGIDE in Caco-2 cells. CONCLUSION: This study showed that peptides from PC, especially IASY and IAGIDE, have therapeutic potential in blood glucose management. © 2026 Society of Chemical Industry.