Isolation of an antihypertensive peptide from alcalase digest of Spirulina platensis.
An angiotensin I-converting enzyme (ACE) inhibitory peptide Ile-Gln-Pro with an IC(50) value of 5.77 +/- 0.09 microM was purified from the alcalase digests of Spirulina platensis by gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography (RP-HPLC). The peptide was synthesized and showed resistance to in vitro digestion by gastrointestinal proteases. Kinetics studies indicated that the peptide was a noncompetitive inhibitor and that the K(i) value was 7.61 +/- 0.16 microM. Oral administration of Ile-Gln-Pro at a dosage of 10 mg/kg showed significant decreases of the weighted systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHR) at 4, 6, and 8 h after treatment. The results showed that the ACE inhibitory peptide from Spirulina platensis may have potential for use in the prevention and treatment of hypertension.
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Jun
J
Lu
Di-Feng
DF
Ren
You-Lin
YL
Xue
Yoriko
Y
Sawano
Takuya
T
Miyakawa
Masaru
M
Tanokura
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry; D004195:Disease Models, Animal; D006801:Humans; D006868:Hydrolysis; D006973:Hypertension / Q000188:drug therapy; D007700:Kinetics; D008297:Male; D010455:Peptides / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D051381:Rats; D011918:Rats, Inbred SHR; D053545:Spirulina / Q000737:chemistry*; D013381:Subtilisins / Q000737:chemistry
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D001426:Bacterial Proteins; D010455:Peptides; D013381:Subtilisins