Identification and Characterization of Osteogenic Peptides from Simulated Infant Gastrointestinal Digestion of Lactopontin

As a key bioactive protein in dairy, lactopontin (LPN) possesses bone-growth properties, but the role of its digestive peptides is unknown. This study investigated the generation and osteogenic activity of LPN-derived peptides using a simulated infant digestion model and peptidomic analysis. Over 90% of LPN was hydrolyzed, generating 242 peptides, with phosphorylated species constituting 76%. Virtual screening with AutoDock Vina selected six candidate peptides with a strong binding affinity for bone morphogenetic protein receptor 1A (BMPR1A). In MC3T3-E1 osteoblasts, two peptides, WLKPDPS and NEpSPEQTDDL, exhibited pronounced osteogenic effects. They significantly enhanced the cell proliferation, alkaline phosphatase activity, and calcium nodule formation. Concurrently, both peptides upregulated the expression of key osteogenic markers, including Bmpr, Runx2, and Ocn. These results highlight LPN-derived digestive peptides as promising bioactive agents for bone health and offer novel nutritional insights.