Proteomic Analysis of ACE Inhibitory Peptides extracted from Fermented Goat Milk

Abstract

Protein extracted from goat milk was hydrolyzed with LH (Lactobacillus Helveticus-cicc22171). Angiotensin Converting Enzyme (ACE) inhibitory peptides were purified from fermented samples of goat milk protein with LH by optimizing incubation time to 8 hours (S-8), 16 hours (S-16), 24 hours (S-24) and 36 hours (S-36), via ultrafiltration. Molecular weight cut-off; 10000 Da (PM-10) membrane was used to perform size exclusion chromatography. Sample with 24 h incubation time was considered as best hydrolyzed as compared to others, by applying Nin-Hydrin reaction and SDS-PAGE analysis. ACE inhibitory assay validated the authenticity of S-24 in inhibiting ACE, in vitro. Furthermore, Q executive Hybrid Quadrapole-Orbitrap Mass Spectrometry was used to determine molecular structure and amino acid sequence of ACE inhibitory peptides. Two protein groups VLPVPQKAVPQ and VLPVPQKVVPQ containing PVP, VVP along with one most abundant peptide TQTPVVVPPFLQPEIMGVPKVKE containing VPP has been identified with highest ACE inhibitory activity on the basis of intensity, small structure and higher concentration of hydrophobic and aromatic amino acids. Fermented goat milk containing these novel bioactive peptides, can be used as nutraceuticals to inhibit ACE and control hypertension.