Discovery, molecular docking, and umami-enhancing synergy of five novel umami peptides from Dictyophora rubrovolvata: Insights into T1R1/T1R3 interaction

Five new umami peptides were isolated from Dictyophora rubrovolvata , enriching natural umami flavor enhancers. • Hydrogen bonding and ionic interactions with T1R1/T1R3 umami taste receptor (e.g., Glu301, His278) underpin the umami taste of Dictyophora rubrovolvata peptides. • Thr-Trp-Glu-Met (TWEM) and Val-Glu-Ser-Glu-Arg (VESER) showed strong umami-boosting effects, suggesting applications in low-sodium, clean-label foods. This study identified and characterized five novel umami peptides — Asn-Gly-Ser-Gly-Gly-Gly-Phe (NGSGGGF), Glu-Gln-Glu-Phe-Asp-Pro-Val (EQEFDPV), Thr-Trp-Glu-Met (TWEM), Asp-Thr-Asn-Pro-Gln-Arg (DTNPQR), and Val-Glu-Ser-Glu-Arg (VESER) — from Dictyophora rubrovolvata protein hydrolysates. Their umami recognition thresholds ranged from 0.125 to 0.50 mg/mL, with TWEM exhibiting the lowest threshold (0.125 mg/mL) and the highest umami intensity. Molecular docking simulations suggested that hydrogen bonding and ionic interactions were the predominant forces mediating peptide–receptor binding, with key recognition residues including Glu105, Glu301, His278, and Ser104 located in the Venus flytrap domains of the T1R1/T1R3 umami taste receptor. Notably, DTNPQR and EQEFDPV exhibited significant umami-enhancing effects when combined with monosodium glutamate, increasing perceived intensity by 73.33% and 53.33%, respectively, suggesting their potential as positive allosteric modulators. These findings provide new insights into the taste mechanisms of Dictyophora rubrovolvata —derived peptides and support their potential as natural umami enhancers in clean-label food formulations. Download: Download high-res image (125KB) Download: Download full-size image