The ENaC taste receptor’s perceived mechanism of mushroom salty peptides revealed by molecular interaction analysis

The ENaC receptor acts as a taste receptor to recognize and perceive salty substances. This study explored the mechanisms by which the ENaC taste receptor recognizes and binds mushroom-derived salty peptides using molecular interaction and molecular simulation. The three subunits α, β, and γ of the ENaC taste receptor (SCNN1α, SCNN1β, and SCNN1γ) showed different recognition characteristics for the salty peptide. The salty peptide binding to the SCNN1α receptor was an entropy-driven reaction, while to SCNN1β and SCNN1γ was an enthalpy-driven reaction. With the salty peptide spatial resistance increasing, salty peptides bind to the ENaC taste receptor shifted from receptor pockets binding to receptor surface binding, with salty octapeptide ESPERPFL preferentially binding to amino acid residues in the receptor pockets 2, 3, and 4, salty nonapeptide KSWDDFFTR and decapeptide RIEDNLVIIR binding to amino acid residues in the pockets 2, 4 and on the surface of the receptor, and salty undecapeptide GQEDYDRLRPL preferentially binding to the atoms on the surface of the receptor. Receptor extracellular arginine, glutamate, aspartate, and lysine residues were the critical amino acid residues recognized to bind salty peptides. The salty peptide-ENaC receptor binding complex was stable around 0.3 nm, and the tight and multisite binding was the main reason the ENaC receptor sensed the salty peptide, enabling it to exert its taste effect. This research can provide a theoretical basis for understanding the taste properties of salty peptides recognized and perceived by the ENaC taste receptor.