Peptide Inhibitors for Angiotensin I-Converting Enzyme from Masai Fermented Milk.

The Masai, a nomad living in East Africa, consume a large quantity of fermented milk as the main staple. Angiotensin I-converting enzyme inhibitory activity of their fermented milk was compared with those of commercial ones. Relatively strong activity was detected in their fermented milk. The inhibitory activity in the milk increased during fermentation with Lactobacillus confusus and Lactococcus lactis subsp. lactis which were isolated from the Masai fermented milk as the dominant strains. Two inhibitory peptides were purified by ethanol fractionation and four HPLC steps. Their amino acid sequence were identified as Ser-Leu-Val-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-His-Asn and Lys-Thr-Thr-Met-Pro-Leu-Trp. Their IC50 values were 38.5 μM and 28.7 μM, respectively.