Murakami M, Tonouchi H, Takahashi R, Kitazawa H, Kawai Y, Negishi H, Saito T
Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, 1-1, Tsutsumidori - Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan.
J Dairy Sci. 2004 Jul;87(7):1967-74. doi: 10.3168/jds.S0022-0302(04)70013-2.
Angiotensin-converting enzyme (ACE) inhibitory activities and anti-hypertensive activities in spontaneously hypertensive rats (SHR) of 12 kinds of commercial peptides of food additive grade were measured. Four peptide products derived from milk proteins showed strong anti-hypertensive activities (>-18.0 mm Hg). A sample of WE80BG derived from whey proteins showed the strongest anti-hypertensive activity (-21.2 +/- 16.9 mm Hg) with a medium level of ACE inhibitory activity (53.6%), and it was subjected to hydrophobic and gel filtration chromatography. From the low molecular weight fraction, an anti-hypertensive peptide was isolated by using reversed-phase HPLC, and it was found to be a tetrapeptide, alanine-leucine-proline-methionine (Ala-Leu-Pro-Met, ALPM), the origin of which was estimated to be beta-lactoglobulin f 142 to 145. At 8 h after oral administration of ALPM in SHR, systolic blood pressure was significantly decreased (-21.4 +/- 7.8 mm Hg), but the IC50 value (concentration of peptide needed to inhibit 50% of the ACE activity) of ALPM was not so high. We named the Ala-Leu-Pro-Met "beta-lactosin B." This peptide is the second anti-hypertensive peptide found from beta-lactoglobulin. Because WE80BG containing ALPM was also found to show the strongest anti-hypertensive activity (-24.5 +/- 10 mm Hg) at 8 h after oral administration in SHR, WE80BG would be suitable for application to the development of a new food expected to have anti-hypertensive effects.
测定了12种食品添加剂级商业肽在自发性高血压大鼠（SHR）中的血管紧张素转换酶（ACE）抑制活性和抗高血压活性。四种源自乳蛋白的肽产品表现出较强的抗高血压活性（>-18.0 mmHg）。一种源自乳清蛋白的WE80BG样品表现出最强的抗高血压活性（-21.2±16.9 mmHg），同时具有中等水平的ACE抑制活性（53.6%），并对其进行了疏水和凝胶过滤色谱分析。从低分子量组分中，通过反相高效液相色谱法分离出一种抗高血压肽，发现它是一种四肽，丙氨酸-亮氨酸-脯氨酸-蛋氨酸（Ala-Leu-Pro-Met，ALPM），其来源估计为β-乳球蛋白f 142至145。在SHR中口服ALPM 8小时后，收缩压显著降低（-21.4±7.8 mmHg），但ALPM的IC50值（抑制50% ACE活性所需的肽浓度）不高。我们将Ala-Leu-Pro-Met命名为“β-乳球蛋白B”。这种肽是从β-乳球蛋白中发现的第二种抗高血压肽。由于含有ALPM的WE80BG在SHR口服给药8小时后也表现出最强的抗高血压活性（-24.5±10 mmHg），因此WE80BG适合应用于开发具有抗高血压作用的新型食品。
