Novel Angiotensin-Converting Enzyme-Inhibitory Peptides From Fermented Bovine Milk Started byKLDS.31 andKLDS.105: Purification, Identification, and Interaction Mechanisms.
Front Microbiol. 2019 ;10:2643. Epub 2019 Nov 28. PMID: 31849852
Fermented milks with strong angiotensin I-converting enzyme (ACE)-inhibitory activity were obtained through a culture withKLDS.31 andKLDS.105 with a fermentation and storage temperature of 37°C. Ultrafiltration fractions with a molecular weight less than 3 kDa in fermented milk whey exhibited the strongest inhibitory activity. Correspondingly, a gastrointestinal digestion experiment showed retention of the bioactivity of these fractions with pepsin and trypsin treatment. Four ACE-inhibitory peptides from fermented milk were isolated, purified by two-step reverse chromatography, and sequenced. Furthermore, the interaction mechanisms between ACE and four isolated peptides were investigated by a molecular docking method and the Independent Gradient Model. Experimental determinationof ICwas done to verify theoretical results. The inhibitory peptide interacted with ACE as follows: Lys-Pro-Ala-Gly-Asp-Phe>Lys-Ala-Ala-Leu-Ser-Gly-Met>Lys-Lys-Ala-Ala-Met-Ala-Met>Leu-Asp-His-Val-Pro-Gly-Gly-Ala-Arg.