title: Short communication: Measuring the angiotensin-converting enzyme inhibitory activity of an 8-amino acid (8mer) fragment of the C12 antihypertensive peptide.
abstract: An 8-AA (8mer) fragment (PFPEVFGK) of a known antihypertensive peptide derived from bovine αS1-casein (C12 antihypertensive peptide) was synthesized by microwave-assisted solid-phase peptide synthesis and purified by reverse phase HPLC. Its ability to inhibit angiotensin-converting enzyme (ACE) was assessed and compared with that of the parent 12mer peptide (FFVAPFPEVFGK) to determine the effect of truncating the sequence on overall hypotensive activity. The activity of the truncated 8mer peptide was found to be almost 1.5 times less active than that of the 12mer, with ACE-inhibiting IC50 (half-maximal inhibitory concentration) values of 108 and 69μM, for the 8mer and 12mer, respectively. Although the 8mer peptide is less active than the original 12mer peptide, its overall activity is comparable to activities reported for other small proteins that elicit physiological responses within humans. These results suggest that microbial degradation of the 12mer peptide would not result in a complete loss of antihypertensive activity if used to supplement fermented foods and that the stable 8mer peptide could have potential as a blood pressure-lowering agent for use in functional foods.
authors.affiliation: Dairy and Functional Foods Research Unit, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038.
authors.forename: Moushumi
authors.initials: M
authors.lastname: Paul
authors.affiliation: Office of the Area Director, North Atlantic Area, Agricultural Research Service, USDA, 600 E. Mermaid Lane, Wyndmoor, PA 19038.
authors.forename: John G
authors.initials: JG
authors.lastname: Phillips
authors.affiliation: Dairy and Functional Foods Research Unit, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038. Electronic address: john.renye@ars.usda.gov.
authors.forename: John A
authors.initials: JA
authors.lastname: Renye
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry*; D000818:Animals; D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D002417:Cattle; D010455:Peptides / Q000737:chemistry
chemical_list: D000596:Amino Acids; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D010455:Peptides
keywords: 8-amino acid peptide; antihypertensive peptide; bovine milk; solid-phase peptide synthesis