Identification and molecular action mechanism of novel TAS2R14 blocking peptides from egg white proteins

Abstract

In this study, potential bitter taste receptor 14 (TAS2R14) blockers were identified from egg white proteins. The novel TAS2R14 blocking peptides DDNK and GVDTK from egg white proteins showed potent bitterness suppression activity, with half maximal inhibitory concentration (IC50) values of 0.1409 ± 0.0033 and 0.1596 ± 0.0029 mg/mL, respectively. Peptide DDNK binds with the quinine-bound amino acid residues (Ile262, Phe247, Trp89, Asn157, and Phe175 of TAS2R14) via four hydrogen bond interactions and one hydrophobic interaction. Peptide GVDTK also binds with the quinine-bound amino acid residues via three hydrogen bond interactions and one hydrophobic interaction. The molecular docking results revealed that hydrogen bond and hydrophobic interactions may play vital roles in blocking the binding of bitter receptor TAS2R14 binding with quinine, and the Asn157, Trp89, and Ile262 residues of TAS2R14 may be the crucial amino acid residues for binding bitter compounds. The novel TAS2R14 blocking peptides DDNK and GVDTK are potential candidates for suppressing bitterness.