The Isolation and Characterization of ACE Inhibitory Peptides from Pelodiscus sinensis Wiegmann Meat and Their Effects on the Viability of HSC-T6 Cells

This study aimed to isolate and identify angiotensin I-converting enzyme (ACE) inhibitory peptides from Chinese soft-shelled turtle (Pelodiscus sinensis Wiegmann) meat. A total of 80 peptides were identified from the active fractions of the papain hydrolysate of the Pelodiscus sinensis meat water-soluble protein, including 78 unique peptides; among them, 47 had identification scores above 50. Of these, 10 peptides were predicted to possess ACE inhibitory potential, good water solubility, and no toxicity and were therefore synthesized for further evaluation. Peptide YK-17 showed the strongest ACE inhibitory activity among the synthesized peptides, with an IC50 value of 479.3 μM, while peptide GK-18 possessed the strongest inhibitory effect on the viability of the hepatic stellate cell line HSC-T6. Molecular docking further indicated that YK-17 formed more hydrogen bonds with N-ACE than with C-ACE, suggesting that YK-17 exhibited stronger hydrogen bonding interactions with N-ACE. These findings suggest that Pelodiscus sinensis meat is a promising source of functional peptides with potential antihypertensive activity and liver fibrosis-related bioactivity.