The structural characteristics of Crassostrea gigas peptide-zinc complexes and the bioactive mechanism of their enhanced zinc absorption

Zinc is an essential mineral for human health, and its deficiency can lead to various health issues. Oysters (Crassostrea gigas) are known to be a rich source of protein-bound zinc. Oyster peptides were complexed with zinc sulfate (ZnSO4) to be oyster peptide-zinc chelates (OPZs) that offer potential as a valuable zinc supplement. The complexation of zinc with oyster peptides induces conformational changes in the peptides, altering their overall spatial arrangement. This could potentially impact their functions and properties. OPZs have demonstrated enhanced physical and gastrointestinal stability, as they are resistant to digestion by pepsin and trypsin. The research has shown that OPZs can modulate the expression of key proteins involved in zinc binding (MT1), peptide transport (PePT1), and zinc transport (ZIP4 and ZnT1) in enterocytes. By regulating the proteins expression, OPZs have the potential to affect zinc absorption and homeostasis. Furthermore, OPZs have been found to enhance zinc absorption through dual pathways compared to the single pathway of inorganic zinc. Additionally, they have the potential to improve zinc bioaccessibility and bioavailability, meaning they can make zinc more easily absorbed by the body and readily available for use.