Identification of antioxidant and ACE‐inhibitory peptides in fermented milk

Abstract

The angiotensin-converting enzyme (ACE)-inhibitory activity and antioxidant properties of a commercial fermented milk from Europe were evaluated. This dairy product showed moderate ACEinhibitory activity and ABTS • + radical-scavenging capacity. The peptides from most active fractions collected by reverse phase high-performance liquid chromatography (RP-HPLC) were sequenced by RP-HPLC-tandem mass spectrometry. This technique allowed rapid identification of peptides included in the most active fractions, and various potentially active peptides were recognised according to previous studies of structure-activity relationship. Three of the identified sequences had previously been described as potent ACE inhibitors. The structure of some sequences substantiated the presence of peptides with ACE-inhibitory, antioxidant and immunomodulatory activities.

Peptergents: Peptide Detergents That Improve Stability and Functionality of a Membrane Protein, Glycerol-3-phosphate Dehydrogenase

“…All three peptergents maintained the activity of the oxidation-sensitive Npx, extending its halflife by up to five times compared to without any reducing agents or peptergents, and the A 6 D:V 6 K mixture conferred the most protection. antioxidant properties; most noteworthy for this study are peptides containing valines and terminal lysines (21,22). As our results indicate, both A 6 D and V 6 K alone confer some oxidation-protective properties but together they retard the time-dependent decrease in activity of Npx.…”

Casein Fermentate of Lactobacillus animalis DPC6134 Contains a Range of Novel Propeptide Angiotensin-Converting Enzyme Inhibitors

“…Peptide SQSKVLPVPQ, corresponding to ␤-casein f(166-175) (IC 50 value, 92 M), has not been reported previously as possessing ACE-inhibitory activity. However, a fragment, KVLPVPQ, corresponding to ␤-casein f(169-175) and reported to have an IC 50 value of 39 M has been previously identified as an ACE inhibitor (18,27). Peptide SKVLPVPQ, which shares eight amino acids with SQSKVLPVPQ, has also demonstrated antihypertensive activity in vivo (58).…”

“…Furthermore, ACE-inhibitory peptides were released from whey and casein following fermentation with different strains of LAB followed by hydrolysis with digestive enzymes (41). Peptides identified were LAYFYP, corresponding to ␣ s1 -casein f(142-147); TTMPLW, corresponding to ␣ s1 -casein f (194)(195)(196)(197)(198)(199); and ␤-casein f(108-113), corresponding to the sequence EMPFPK, in addition to two ACE-inhibitory peptides from whey, GLDIQK, corresponding to ␤-lactoglobulin (␤-Lg) f (9)(10)(11)(12)(13)(14), and VAGTWY, corresponding to ␤-Lg f (15)(16)(17)(18)(19)(20) (41). Characterization of ACE-inhibitory peptides produced during casein degradation has been described for L. helveticus (14,58) and to a lesser extent for Lactobacillus casei (8).…”

Antihypertensive Properties of Plant Protein Derived Peptides

“…Fermented milk products prepared using different strains of lactic acid bacteria have been found to exert antihypertensive and antioxidative activities [71,72]. Moreover, several antioxidative and ACE-inhibitory peptide sequences have been identified from fermented milk [73]. Only few experimental investigations to produce these compounds by fermentation of plant proteins have been reported.…”