Preparation and characterization of novel bioactive peptides responsible for angiotensin I-converting enzyme inhibition from wheat germ.
Reported is the preparation of wheat germ (WG) hydrolyzate with potent angiotensin I-converting enzyme (ACE) inhibitory activity, and the characterization of peptides responsible for ACE inhibition. Successful hydrolyzate with the most potent ACE inhibitory activity was obtained by 0.5 wt.%-8 h Bacillus licheniformis alkaline protease hydrolysis after 3.0 wt.%-3 h alpha-amylase treatment of defatted WG (IC50; 0.37 mg protein ml(-1)). The activity of WG hydrolyzate was markedly increased by ODS and subsequent AG50W purifications (IC50; 0.018 mg protein ml(-1)). As a result of isolations by high performance liquid chromatographies, 16 peptides with the IC50 value of less than 20 microM, composed of 2-7 amino acid residues were identified from the WG hydrolyzate. Judging from the high content (260 mg in 100 g of AG50W fraction) and powerful ACE inhibitory activity (IC50; 0.48 microM), Ile-Val-Tyr was identified as a main contributor to the ACE inhibition of the hydrolyzate.
Matsui
T
T
Department of Food Science and Technology, Kyushu University, Fukuoka, Japan. tmatsui@agr.kyushu-u.acjp
Li
C H
CH
Osajima
Y
Y
D000469:Alkaline Phosphatase / Q000378:metabolism; D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange; D006868:Hydrolysis; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D014908:Triticum / Q000737:chemistry* / Q000378:metabolism
D000806:Angiotensin-Converting Enzyme Inhibitors; D002411:Cation Exchange Resins; D009842:Oligopeptides; D000469:Alkaline Phosphatase