Antihypertensive Effect of Angiotensin I Converting Enzyme-Inhibitory Peptide from Hydrolysates of Bigeye Tuna Dark Muscle, Thunnus obesus

• Published in: Journal of agricultural and food chemistry Vol. 55; no. 21; pp. 8398 - 8403
• Main Authors: Qian, Zhong-Ji, Je, Jae-Young, Kim, Se-Kwon
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 17.10.2007
• Subjects: ACE inhibitory peptide; Amino Acid Sequence; angiotensin I converting enzyme inhbitors; Angiotensin-Converting Enzyme Inhibitors - isolation & purification; Angiotensin-Converting Enzyme Inhibitors - pharmacology; Animals; Antihypertensive Agents - pharmacology; antihypertensive effect; bioactive constituent; Biological and medical sciences; dark muscle; enzyme inhibitors; Food industries; Fundamental and applied biological sciences. Psychology; Hydrolysis; hypertension; kinetics; Male; Muscle Proteins - chemistry; Muscle Proteins - isolation & purification; Muscles - chemistry; oral administration; Peptide Hydrolases - metabolism; peptides; Peptides - chemistry; Peptides - isolation & purification; Peptides - pharmacology; protein hydrolysates; Rats; Rats, Inbred SHR; skeletal muscle; Thunnus obesus; Tuna; tuna dark muscle; antihypertensive effect; kinetics; ACE inhibitory peptide; tuna dark muscle; Peptides; Enzyme; Peptidases; Hydrolysate; Peptidyl-dipeptidase A; Tuna (Tunny fish); antihypertensive effect; Hydrolases; Peptidyl-dipeptidases; Muscle; Kinetics; ACE inhibitor
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0710635

Angiotensin I converting enzyme (ACE) inhibitory peptide was isolated from tuna dark muscle hydrolysate prepared by alcalase, neutrase, pepsin, papain, α-chymotrypsin, and trypsin, respectively. Among hydrolysates, the pepsin-derived hydrolysate exhibited the highest ACE I inhibitory activity versus those of other enzyme hydrolysates. The structure of the peptide was identified to be Trp-Pro-Glu-Ala-Ala-Glu-Leu-Met-Met-Glu-Val-Asp-Pro (molecular weight 1581 Da) by time of flight mass spectrometry/mass spectrometry analysis, and the IC50 value of the peptide was 21.6 µM. The Lineweaver–Burk plots revealed that the peptide acts as a noncompetitive inhibitor, and the inhibitor constant (K i) was calculated as 26.6 µM using the secondary plots. The peptide had an antihypertensive effect according to the time-course measurement after oral administration to spontaneously hypertensive rats. Maximal reduction was detected 3 h after oral administration at a dose of 10 mg/kg of body weight. These results suggest that the peptide derived from tuna dark muscle would be a beneficial ingredient for functional food or pharmaceuticals against hypertension and its related diseases.