Angiotensin- I- converting enzyme (ACE) inhibitory peptides from Pacific cod skin gelatin using ultrafiltration membranes

•Gelatin was isolated from Pacific cod skin, seafood processing byproduct.•Two bioactive peptides GASSGMPG (662 Da) and LAYA (436 Da) were purified.•Peptides showed potent ACE inhibition with IC50 values of 6.9 and 14.5 μM.•Molecular mechanism of peptides and ACE was conducted by computational docking.•Peptides could be used as functional ingredients for improving cardiovascular health.

Angiotensin- I- converting enzyme (ACE) is crucial in the control of hypertension and the development of type- 2 diabetes and other diseases associated with metabolic syndrome. The aim of this work was to utilize Pacific cod skin to purify ACE inhibitory peptides. First, gelatin was extracted from Pacific cod skin and hydrolyzed with several enzymes (pepsin, papain, α-chymotrypsin, trypsin, neutrase, and alcalase). The pepsin hydrolysate showed the strongest ACE inhibitory effect and was further fractionated into different ranges of molecular weight (<1, 1-5, 5-10, and >10 kDa) using ultrafiltration (UF) membranes. The peptic hydrolysate below 1 kDa resulted in two potent ACE inhibitory peptides, GASSGMPG (662 Da) and LAYA (436 Da), with IC50 values (concentration required to decrease the ACE activity by 50%) of 6.9 and 14.5 μM, respectively. Moreover, to explore the interaction between the peptides and ACE molecule, the tertiary structure of ACE and docking simulation to the peptides were predicted using Docking Server. Pacific cod peptides can be used as functional food ingredients to prevent hypertension and its related diseases.

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