Desalted Duck Egg White Peptides: Promotion of Calcium Uptake and Structure Characterization

The effects of desalted duck egg white peptides (DPs) on calcium absorption were investigated in three models: Caco-2 cell monolayer model, Caco-2 cell population model, and everted intestinal sac model. DPs were found to enhance calcium transport and may do so by acting as calcium carriers and interacting with the cell membrane to open a special Ca2+ channel, whereas the paracellular pathway may make only a minor contribution. Structure characterization demonstrated the important roles of seven crucial peptides, such as VSEE and LYAEE, in binding calcium and promoting calcium uptake. Three synthetic peptides (VHSS, VSEE, and VHS(p)S(p)) potently induced calcium transport in Caco-2 monolayers, with VHS(p)S(p) being the most effective. This research expands the understanding of the mechanism of cellular calcium uptake by DPs as well as highlights an opportunity for recycling an otherwise discarded processing byproduct.