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.
Lu
Jun
J
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Ren
Di-Feng
DF
Xue
You-Lin
YL
Sawano
Yoriko
Y
Miyakawa
Takuya
T
Tanokura
Masaru
M
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