α-Casein group of proteins makes up to 65% of the total casein and consists of αS1- casein, αS2- casein and other related proteins. Among all the proteases employed, chymotryptic peptides showed maximum inhibition for angiotensin converting enzyme (ACE). The degree of hydrolysis and release kinetics of the peptides during chymotrypsin hydrolysis was compared with biological activity and the potent peptides fractions were identified. The crude fraction obtained after 110 min of hydrolysis shows multifunctional activities, like ACE inhibition, antioxidant activity, prolyl endopeptidase inhibitory activity and antimicrobial activities. This fraction was further purified by HPLC and sequenced by mass spectra. This fraction constituted peptides with molecular weights of 1,205, 1,718 Da respectively. The sequencing of peptides by MALDI-TOF MS/MS shows sequences QKALNEINQF and TKKTKLTEEEKNRL from α-S2 casein.
Matrix assisted laser desorption ionization time of flight
Prolyl endo peptidase
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Author S. Srinivas gratefully acknowledges the senior research fellowship during the course of the investigation from Council of Scientific and Industrial Research (CSIR), New Delhi, India.
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