Seventeen novel angiotensin converting enzyme (ACE) inhibitory peptides from the protein hydrolysate of Mytilus edulis: isolation, identification, molecular docking study, and protective function on HUVECs

In the study, seventeen angiotensin converting enzyme (ACE) inhibitory peptides were isolated from the protein hydrolysate of blue mussel (Mytilus edulis) and identified as MFR, MFV, FV, KP, QP, QVK, IK, YKV, IRK, MLKV, NFRPQ, YEGDP, WF, GPE, SWISS, SVEWK, and FKWH, respectively. Among them, IK, YEGDP, WF, and SWISS showed the strongest ACE inhibitory activity with IC50 values of 0.77 +/- 0.020, 0.19 +/- 0.010, 0.40 +/- 0.015, and 0.32 +/- 0.017 mg mL(-1), respectively. Molecular docking study indicated that IK, YEGDP, WF, and SWISS exhibited better inhibitory activity attributed to its effective interaction with the active site of ACE by hydrogen bonding, electrostatic force and hydrophobic interaction. Furthermore, IK, YEGDP and WF perform an important protective function on human umbilical vein endothelial cells (HUVECs) by increasing nitric oxide (NO) content, decreasing endothelin-1 (ET-1) secretion, and antagonizing the adverse impact of norepinephrine on the secretion of NO and ET-1. In addition, YEGDP and WF could provide protection to HUVECs against H2O2 damage by increasing superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and NO levels to decrease the contents of reactive oxygen species (ROS) and malondialdehyde. Therefore, seventeen ACE inhibitory peptides, especially YEGDP and WF, might be used as natural ingredients for the development of products with antihypertensive functions.

Automated summary

In this study, seventeen ACE inhibitory peptides were isolated from blue mussel protein hydrolysate. Four of these peptides, IK, YEGDP, WF, and SWISS, showed the strongest ACE inhibitory activity. Molecular docking study revealed that these peptides interacted effectively with the active site of ACE, resulting in better inhibitory activity. Additionally, some of the peptides demonstrated protective effects on human umbilical vein endothelial cells (HUVECs) by reducing harmful substance secretion and increasing nitric oxide content.