Abstract
Urea-denatured α-zein was almost completely hydrolyzed into small peptides by digestion with 1/100 (w/w) of thermolysin at 37°C for 3h. The angiotenisin I-converting enzyme (ACE) inhibitory activity (IC50 of the thermolysin digest of total α-zein was 24.5μg/ml, and most of the peptide fractions from Z19 α-zein and total α-zein separated by reverse-phase HPLC had more or less ACE inhibitory activity. From these fractions, thirty-six peptides, including 5 dipeptides, 14 tripeptides, 9 tetrapeptides, 5 pentapeptides, and 3 hexapeptides, were purified and their amino acid sequences were determined.
