Bioactive Peptides from Bovine Milk a-Casein: Isolation, Characterization and Multifunctional properties

a-Casein group of proteins makes up to 65% of
the total casein and consists of aS1- casein, aS2- 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 a-S2 casein.