title: Novel angiotensin I-converting enzyme inhibitory peptide derived from bovine casein.
abstract: Bovine lactic casein was hydrolysed using a combination of three enzymes, namely, subtilisin, bacillolysin, and trypsin, and the resulting preparation was coined CH-3. CH-3 showed angiotensin I-converting enzyme (ACE)-inhibitory activity (IC50: 74 μg/mL). A single oral administration of CH-3 led to a transient but significant decrease in the systolic blood pressure (SBP) of spontaneously hypertensive rats (SHRs), while daily oral administration of CH-3 for 28 consecutive days led to a lower rate of SBP increase. The CH-3 preparation was then fractionated and the αS2-casein-derived tripeptide Met-Lys-Pro (or MKP) was identified as a novel peptide with strong ACE-inhibitory activity (IC50=0.12 μg/mL, 0.3 μM). The MKP peptide constituted only 0.053% of CH-3 but its activity was accounted for 33% of the total ACE-inhibitory activity of CH-3. In addition, a single oral administration of MKP also led to a transient but significant decrease in the SBP of SHRs.
authors.affiliation: Morinaga Milk Industry Co., Ltd., Functional Food Research Department Food Science & Technology Institute, 1-83 5-Chome, Higashihara, Zama, Kanagawa 252-8583, Japan. a_yamada@morinagamilk.co.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Yamada
authors.forename: Takuma
authors.initials: T
authors.lastname: Sakurai
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ochi
authors.forename: Eri
authors.initials: E
authors.lastname: Mitsuyama
authors.forename: Koji
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Abe
mesh_terms: D000284:Administration, Oral; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000737:chemistry; D001794:Blood Pressure / Q000187:drug effects; D002364:Caseins / Q000737:chemistry*; D002417:Cattle; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D010455:Peptides / Q000008:administration & dosage* / Q000737:chemistry; D007703:Peptidyl-Dipeptidase A / Q000032:analysis; D011492:Protein Hydrolysates / Q000737:chemistry*; D051381:Rats; D011918:Rats, Inbred SHR
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; C000622057:CH-3 casein hydrolysate; D002364:Caseins; D010455:Peptides; D011492:Protein Hydrolysates; D007703:Peptidyl-Dipeptidase A
keywords: Angiotensin I-converting enzyme; Casein; Hydrolysate; MKP; Met-Lys-Pro