Peptide identification in a porcine gelatin prolyl endoproteinase hydrolysate with angiotensin converting enzyme (ACE) inhibitory and hypotensive activity

Abstract

A targeted enzymatic approach was employed for the generation of angiotensin converting enzyme (ACE) inhibitory/anti-hypertensive peptides. Porcine skin gelatin was hydrolysed with Aspergillus niger prolyl endoproteinase (An-PEP) to produce an hydrolysate with potent ACE inhibitory activity (mean IC50: 220.2µgmL−1) after 4-h hydrolysis. Peptide identification was achieved by UPLC-ESI-MS/MS. The ACE-inhibitory activity of a selection of the identified peptides was determined. The most potent peptide was Met-Gly-Pro with an ACE IC50 of 51.11±1.14µM. Furthermore, oral administration (50mg/kg body weight) of the hydrolysate to spontaneously hypertensive rats resulted in decreases in systolic and diastolic blood pressure of −28.89±5.11 and −22.86±5.65mmHg, respectively. Mean arterial pressure and heart rate were also reduced (−25.99±5.66mmHg and −53.63±17.67bpm, respectively). The beneficial in vivo effects may be related to the potent C-terminal containing proline ACE-inhibitory peptides in the hydrolysate.