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

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: 220.2 mu g mL(-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 +/- 1.14 mu M. Furthermore, oral administration (50 mg/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 +/- 5.65 mm Hg, respectively. Mean arterial pressure and heart rate were also reduced (-25.99 +/- 5.66 mm Hg and 53.63 +/- 17.67 bpm, respectively). The beneficial in vivo effects may be related to the potent C-terminal containing proline ACE-inhibitory peptides in the hydrolysate. (C) 2017 Elsevier Ltd. All rights reserved.