title: Latent production of angiotensin I-converting enzyme inhibitors from buckwheat protein.
abstract: The latent production of angiotensin I-converting enzyme (ACE) Inhibitors from tartary buckwheat (BW) was investigated, and the peptides responsible for ACE inhibition characterized. Intact buckwheat was found to exhibit ACE inhibitory activity having an IC50 value of 3.0 mg/ml. The activity of the protein fraction (IC50: 0.36 mg protein/ml) was not enhanced by pepsin treatment. Pepsin, followed by chymotrypsin and trypsin hydrolysis, resulted in a significant increase in the ACE inhibitory activity (IC50: 0.14 mg protein/ml). The rutin contained in the buckwheat did not exhibit any ACE inhibition. A single oral administration of BW digest lowered the systolic blood pressure of a spontaneously hypertensive rat. Thus, BW proteins offer a potential resource for producing ACE inhibitory peptides during the digestion process. From the di-/tri-peptide fraction (DTPF) of the BW digest, inhibitory peptides were identified. The magnitude (%) of the total ACE inhibitory contribution of each identified peptide, relative to the overall inhibition of the DTPF, was about 41%.
authors.affiliation: Faculty of Agriculture, Division of Bioresource and Bioenvironmental Sciences, Graduate School Kyushu University, Fukuoka, Japan.
authors.forename: Chun-Hui
authors.initials: CH
authors.lastname: Li
authors.forename: Toshiro
authors.initials: T
authors.lastname: Matsui
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Rikio
authors.initials: R
authors.lastname: Yamasaki
authors.forename: Terukazu
authors.initials: T
authors.lastname: Kawasaki
mesh_terms: D000284:Administration, Oral; D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D010450:Endopeptidases / Q000378:metabolism; D019612:Fagopyrum / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D006973:Hypertension / Q000188:drug therapy; D020128:Inhibitory Concentration 50; D008297:Male; D009842:Oligopeptides / Q000302:isolation & purification / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D012431:Rutin / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D009842:Oligopeptides; D010455:Peptides; D012431:Rutin; D010450:Endopeptidases