title: Isolation and antihypertensive effect of angiotensin I-converting enzyme (ACE) inhibitory peptides from spinach Rubisco.
abstract: Four new inhibitory peptides for angiotensin I-converting enzyme (ACE), that is, MRWRD, MRW, LRIPVA, and IAYKPAG, were isolated from the pepsin-pancreatin digest of spinach Rubisco with the use of HPLC. IC(50) values of individual peptides were 2.1, 0.6, 0.38, and 4.2 microM, respectively. MRW and MRWRD had an antihypertensive effect after oral administration to spontaneously hypertensive rats. Maximal reduction occurred 2 h after oral administration of MRW, whereas MRWRD showed maximal decrease 4 h after oral administration at doses of 20 and 30 mg/kg, respectively. IAYKPAG also exerted antihypertensive activity after oral administration at the dose of 100 mg/kg, giving a maximum decrease 4 h after oral administration. IAYKP, IAY, and KP, the fragment peptides of IAYKPAG, also exerted antihypertensive activity. LRIPVA [corrected] did not show any antihypertensive effect at a dose of 100 mg/kg despite its potent ACE-inhibitory activity.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Yang
authors.forename: Ewa D
authors.initials: ED
authors.lastname: Marczak
authors.forename: Megumi
authors.initials: M
authors.lastname: Yokoo
authors.forename: Hachiro
authors.initials: H
authors.lastname: Usui
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000302:isolation & purification* / Q000627:therapeutic use*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D010194:Pancreatin / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use*; D051381:Rats; D011918:Rats, Inbred SHR; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry*; D018724:Spinacia oleracea / Q000737:chemistry* / Q000201:enzymology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010446:Peptide Fragments; D010194:Pancreatin; D010434:Pepsin A; D012273:Ribulose-Bisphosphate Carboxylase