Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium.
J Agric Food Chem. 2011 Jan 26;59(2):552-8. doi: 10.1021/jf1037823. Epub 2010 Dec 21.
In this project we report on the angiotensin I-converting enzyme (ACE)-inhibitory activity of a bovine gelatin hydrolysate (Bh2) that was submitted to further hydrolysis by different enzymes. The thermolysin hydrolysate (Bh2t) showed the highest in vitro ACE inhibitory activity, and interestingly a marked in vivo blood pressure-lowering effect was demonstrated in spontaneously hypertensive rats (SHR). In contrast, Bh2 showed no effect in SHR, confirming the need for the extra thermolysin hydrolysis. Hence, an angiotensin I-evoked contractile response in isolated rat aortic rings was inhibited by Bh2t, but not by Bh2, suggesting ACE inhibition as the underlying antihypertensive mechanism for Bh2t. Using mass spectrometry, seven small peptides, AG, AGP, VGP, PY, QY, DY and IY or LY or HO-PY were identified in Bh2t. As these peptides showed ACE inhibitory activity and were more prominent in Bh2t than in Bh2, the current data provide evidence that these contribute to the antihypertensive effect of Bh2t.
在本项目中，我们报告了一种牛明胶水解物（Bh2）的血管紧张素转化酶（ACE）抑制活性，该水解物已通过不同的酶进一步水解。其中，糜蛋白酶水解物（Bh2t）表现出最高的体外 ACE 抑制活性，有趣的是，它在自发性高血压大鼠（SHR）中表现出明显的降血压作用。相比之下，Bh2 在 SHR 中没有效果，这证实了需要额外的糜蛋白酶水解。因此，Bh2t 抑制了分离的大鼠主动脉环中血管紧张素 I 引起的收缩反应，但 Bh2 没有，这表明 ACE 抑制是 Bh2t 降压的潜在机制。通过质谱分析，在 Bh2t 中鉴定出七种小肽，分别为 AG、AGP、VGP、PY、QY、DY 和 IY 或 LY 或 HO-PY。由于这些肽具有 ACE 抑制活性，并且在 Bh2t 中比在 Bh2 中更为突出，因此目前的数据提供了证据表明这些肽有助于 Bh2t 的降压作用。
