血管紧张素转换酶（ACE）的提取与活性验证

在从紫菜中提取制备降血压肽的研究中，为筛选能够抑制血管紧张素转换酶（ACE）活性的功能肽，需要大量ACE进行体外检测。但ACE成本昂贵，本文利用硫酸铵分级盐析法提取猪肺组织中的ACE，测其酶活力为15．45×10^-3U／mg，比活力为33．80×10^-3U／mg。通过卡托普利来验证其抑制效果，抑制率达49．15％。采用本实验室初步制得的紫菜降血压肽对自制ACE和商品ACE的活性进行抑制，测定IC50发现该抑制剂对2种ACE的抑制效果差异不大，且活性较为稳定，因此所提取的ACE粗酶液可直接用于降血压肽的体外检测实验。

Extraction and Activity Verification of Angiotensin Converting Enzyme

At present, a research of preparing angiotensin converting enzyme inhibitory pepfides from alga has been conducted in our laboratory, which required a large amount of expensive ACE to filter and detect the activity of functional peptides in vitro. Therefore, in this study, ACE was fraetionated from pig＇s lung organism, with the method of ammonium sulfate precipitation and salting out, whose enzyme activity was tested to be 15.45×10^-3 U/mg, and the specific activity was 33. 80×10^-3 U/mg. Using Captopril to inhibit the activity of ACE, the inhibitory percentage reached to 49. 15%. According to the experiments of laver antihypertensive peptides, prepared by our laboratory, inhibiting the activity of ACE both extracted and commercially purchased, there were no significant differences between two IC50 detected, and the activity of ACE extracted was stable, indicating that it could be used directly in the detection of ACE inhibition peptides in vitro.