A novel ACE inhibitory peptide isolated from Acaudina molpadioidea hydrolysate.
Body wall protein from the sea cucumber (Acaudina molpadioidea) was hydrolyzed sequentially with bromelain and alcalase. The hydrolysate was fractionated into two ranges of molecular weight (PH-I, >2 kDa; PH-II, <2kDa) using an ultrafiltration membrane bioreactor system. The PH-II brought about a high angiotensin I-converting enzyme (ACE) inhibitory activity. An ACE inhibitory peptide was isolated from the PH-II, using the chromatographic methods including gel filtration, ion-exchange chromatography and reversed phase high-performance liquid chromatography. The purified ACE inhibitory peptide was a novel peptide, showing very low similarity to other ACE inhibitory peptide sequences, and was sequenced as MEGAQEAQGD. It was found that the inhibitory activity of the peptide was intensified by 3.5 times from IC(50) 15.9 to IC(50) 4.5 microM after incubation with gastrointestinal proteases. The ACE inhibitory peptide from A. molpadioidea showed a clear antihypertensive effect in spontaneously hypertensive rats (SHR), at a dosage of 3 microM/kg.
Zhao
Yuanhui
Y
College of Food Science and Engineering, Ocean University of China, Qingdao, China.
Li
Bafang
B
Dong
Shiyuan
S
Liu
Zunying
Z
Zhao
Xue
X
Wang
Jingfeng
J
Zeng
Mingyong
M
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D006868:Hydrolysis; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification* / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D012616:Sea Cucumbers / Q000737:chemistry*; D013997:Time Factors
D000806:Angiotensin-Converting Enzyme Inhibitors; D010446:Peptide Fragments; D007703:Peptidyl-Dipeptidase A