Separation and identification of ACE inhibitory peptides from Ruditapes philippinarum and molecular docking

Objective: To select the bioactive peptides quickly and accurately from Ruditapes philippinarum hydrolysate.Methods: Peptides from Ruditapes philippinarum hydrolysate could be separated by ultrafiltration and ion exchange chromatography based on the ACE inhibitory assay- direct fractionation. Then amino acids sequences of peptides were identified according to the MS / MS spectra and protein database. Interaction mechanism between the peptides and ACE was investigated by molecular docking. Results: 67 peptides were identified,among which four peptides,QIIVQDLTKR,LDYRPGDKFKGT,NTQIIVQDLTKR and LLFDRAPVNFGNYR,can bind to ACE stably. Our docking results also suggested that the ACE inhibitory peptides bind to ACE via interactions with Glu403,Ala356 and Arg522 residues and the residue Glu403 might be a significant binding site.Conclusions: this study can quickly select,identify and evaluate the bioactive peptides while finding potential binding sites between bioactive peptides and ACE,which provides the basis and reference for further research.