Li Chun-Hui, Matsui Toshiro, Matsumoto Kiyoshi, Yamasaki Rikio, Kawasaki Terukazu
Faculty of Agriculture, Division of Bioresource and Bioenvironmental Sciences, Graduate School Kyushu University, Fukuoka, Japan.
J Pept Sci. 2002 Jun;8(6):267-74. doi: 10.1002/psc.387.
The latent production of angiotensin I-converting enzyme (ACE) Inhibitors from tartary buckwheat (BW) was investigated, and the peptides responsible for ACE inhibition characterized. Intact buckwheat was found to exhibit ACE inhibitory activity having an IC50 value of 3.0 mg/ml. The activity of the protein fraction (IC50: 0.36 mg protein/ml) was not enhanced by pepsin treatment. Pepsin, followed by chymotrypsin and trypsin hydrolysis, resulted in a significant increase in the ACE inhibitory activity (IC50: 0.14 mg protein/ml). The rutin contained in the buckwheat did not exhibit any ACE inhibition. A single oral administration of BW digest lowered the systolic blood pressure of a spontaneously hypertensive rat. Thus, BW proteins offer a potential resource for producing ACE inhibitory peptides during the digestion process. From the di-/tri-peptide fraction (DTPF) of the BW digest, inhibitory peptides were identified. The magnitude (%) of the total ACE inhibitory contribution of each identified peptide, relative to the overall inhibition of the DTPF, was about 41%.
研究了苦荞中血管紧张素I转换酶（ACE）抑制剂的潜在产生，并对负责ACE抑制的肽进行了表征。发现完整的苦荞具有ACE抑制活性，IC50值为3.0 mg/ml。胃蛋白酶处理不会增强蛋白质部分的活性（IC50：0.36 mg蛋白质/ml）。胃蛋白酶处理后，再经胰凝乳蛋白酶和胰蛋白酶水解，导致ACE抑制活性显著增加（IC50：0.14 mg蛋白质/ml）。苦荞中含有的芦丁未表现出任何ACE抑制作用。单次口服苦荞消化物可降低自发性高血压大鼠的收缩压。因此，苦荞蛋白是消化过程中产生ACE抑制肽的潜在来源。从苦荞消化物的二肽/三肽部分（DTPF）中鉴定出了抑制肽。相对于DTPF的总体抑制作用，每种鉴定出的肽对总ACE抑制作用的贡献幅度（%）约为41%。
