Isolation and Characterization of Angiotensin Converting Enzyme Inhibitory Peptide from Buffalo Casein

Angiotensin-converting enzyme (ACE) enhances blood pressure by making potential vasoconstrictor, Angiotensin-II from Angiotensin-I. Thus, it is the key target enzyme in cardiovascular disease therapy. Hence, in the present study an attempt has been made for identification and characterization of ACE inhibitory peptide from buffalo milk casein. Buffalo milk casein was isolated and digested with different digestive enzymes (pepsin, trypsin, chymotrypsin and their combination). Pepsin-Trypsin hydrolysates shown highest (72.55 ± 2.23%/50 μg) ACE inhibitory activity, in further ultra-filtration, < 1 kDa fraction shown the highest inhibitory activity among the other fractions. Below 1 kDa filtrate was further fractionated through RP-HPLC, fraction 11 exhibited the highest ACE inhibitory activity. Out of 15 peptides of 11th fraction (LC–MS/MS sequence) VLPVPQK is the novel peptide, which shown significant ACEI activity. Therefore, this study supports the notion that milk is a very good nutraceutical, and the novel peptide sequence can be utilized in commercial peptide synthesis for making functional food preparation.