title: Porcine skeletal muscle troponin is a good source of peptides with Angiotensin-I converting enzyme inhibitory activity and antihypertensive effects in spontaneously hypertensive rats.
abstract: In the search for novel peptides that inhibit the angiotensin I-converting enzyme (ACE), porcine skeletal troponin was hydrolyzed with pepsin, and the products were subjected to various types of chromatography to isolate active peptides. Glu-Lys-Glu-Arg-Glu-Arg-Gln (EKERERQ) and Lys-Arg-Gln-Lys-Tyr-Asp-Ile (KRQKYDI) were identified as active peptides, and their 50% inhibitory concentrations were found to be 552.5 and 26.2 microM, respectively. These are novel ACE inhibitory peptides, and the activity of KRQKYDI was the strongest among previously reported troponin-originated peptides. KRQKYDI was slowly hydrolyzed by treatment with ACE, and kinetic studies indicated that this peptide was a competitive inhibitor of the enzyme. When KRQKYDI was administered orally to spontaneously hypertensive rats (SHR) at a dose of 10 mg/kg, a temporary antihypertensive activity was observed at 3 and 6 h after administration.
authors.affiliation: Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Katayama
authors.forename: Henny Endah
authors.initials: HE
authors.lastname: Anggraeni
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mori
authors.forename: Abdulatef M
authors.initials: AM
authors.lastname: Ahhmed
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawahara
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakayama
authors.forename: Masugi
authors.initials: M
authors.lastname: Maruyama
authors.forename: Michio
authors.initials: M
authors.lastname: Muguruma
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D006973:Hypertension / Q000188:drug therapy; D018482:Muscle, Skeletal / Q000737:chemistry*; D010434:Pepsin A / Q000378:metabolism; D010446:Peptide Fragments / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D013552:Swine; D014336:Troponin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010446:Peptide Fragments; D014336:Troponin; D010434:Pepsin A