Identification and molecular mechanism of a tri-peptide inhibitor targeting iNOS from duck embryo protein hydrolysates by experimental and bioinformatics studies

Duck embryonic proteins are a promising source of food-derived functional peptides. Using a combination of experiments and bioinformatics approaches, a tri-peptide inhibitor YPW targeting iNOS was identified from duck embryo protein hydrolysates. Our results indicated that YPW could significantly inhibit LPS-induced NO generation in macrophages in a dose-dependent manner. YPW also significantly inhibited the expression of IL-6 and iNOS. Molecular simulations revealed that YPW could interact strongly with (iNOS) with a binding energy of -45.71 ± 17.75 kJ/mol. The stability of YPW-iNOS was maintained by the hydrogen bonds of amino acid residues Ile195, Gly196, Gly365, Glu371, Asn364, and Trp366, and the hydrophobic interactions by Trp188, Phe363, and Val346. In conclusion, our study provides a new idea for broadening the utilization of duck embryo proteins, and a strategy for the discovery of food-derived bioactive peptides.