Exploring of novel salt-enhancing peptides from manila clam: isolation, peptidomics and molecular characteristics

This paper aimed to explore salt-enhancing peptides from the hydrolysates of Manila clam. Firstly, 265 peptides were identified in the hydrolysates of Manila clams. Then, 26 bioactive peptides were selected for molecular docking with the TMC4 receptor. Finally, peptides LF9 (−120.41 kcal/mol), EM9 (−118.10 kcal/mol), and SH9 (−112.49 kcal/mol) showed better docking affinities. Van der Waals forces and hydrogen bonding were the main binding forces, with ARG583 and GLU286 identified as key residues. E -tongue showed that the three peptides had salt-enhancing effects: SH9 (8.93) > EM9 (3.77) > LF9 (3.22). The SH9-TMC4, EM9-TMC4, and LF9-TMC4 complexes reached equilibrium within 50 ns in molecular dynamics simulations. The quantum chemistry analysis revealed that the active sites of LF9, SH9, and EM9 are C24C25, C56C57, and C58S59, corresponding to HIS, GLN, and GLU, respectively. The discovery of three salt-enhancing peptides contributed to the development of novel salt enhancers and provided new theoretical insights.