Structural characterization and functional evaluation of deer sinew peptide-calcium chelate for intestinal calcium...

Deer sinew is rich in collagen, making it an excellent raw material for preparing bioactive peptides. This study developed functional foods by combining deer sinew peptides with calcium ions to form deer sinew peptide calcium chelates (DSPs-Ca). The preparation, characterization, and stability assessment of DSPs-Ca were conducted. Utilizing Caco-2 cell monolayer and MC3T3-E1 osteoblast models, the mechanism of action promoting intestinal calcium absorption and inducing osteoblast differentiation and mineralization was investigated at the gene and protein levels. Results showed that process-optimized DSPs-Ca exhibited excellent stability under various physiological conditions. In the Caco-2 monolayer model, DSPs-Ca significantly enhanced calcium ion transmembrane transport and increased the expression of calcium channel-related genes and proteins (TRPV6, Calbinin-D9k, and PMCA1b), suggesting it may improve calcium bioavailability by regulating intestinal calcium absorption pathways. In addition, DSPs-Ca significantly promoted the proliferation, differentiation, and mineralization processes of MC3T3-E1 pre-osteoblasts, enhancing their horizontal and spatial migration capabilities. Further analysis showed that DSPs-Ca upregulates the expression of osteogenesis-related genes and proteins. Therefore, DSPs-Ca may have a dual function of promoting calcium absorption and bone formation.