Isolation and characterization of novel umami peptides from dried-salted large yellow croaker (Larimichthys crocea) and molecular docking to the T1R1/T1R3 taste receptor

This study aimed to extract umami peptides from East China dried-salted yellow croaker (Larimichthys crocea) and explore their flavor properties and binding mechanisms. Using ultrafiltration, gel column chromatography, and reverse-phase high-performance liquid chromatography, twelve peptide components were identified, with five selected for further analysis: Asp-Leu-Tyr-Glu (DLYE), Glu-Pro-Arg-His-Thr (EPRHT), Leu-Glu-Asn-Ser (LENS), Leu-Pro-Ile-Glu-Asp (LPIED), and Ser-Phe-Arg-Ala-Asn (SFRAN). Sensory evaluation confirmed that all five peptides enhanced freshness in taste. Computational analysis, including Modeller10.2 and ZDock, revealed a high-quality model of the T1R1/T1R3 receptor, with 97.7 % of the amino acid residues within the allowable range, thereby verifying model accuracy. Usually, T1R1 and T1R3 have different conformations, and the Venus flytrap domain (VFTD) in the cavity of T1R3 is beneficial for binding umami peptides. Key binding sites (Glu65, Arg393, and Gly389) were identified in the T1R1 subunit. These findings provide insight into the flavor characteristics and binding mechanisms of umami peptides from yellow croaker, offering a theoretical foundation for their application in flavor enhancement.