Zeitlin I J, Parratt J R, Fagbemi O
Department of Physiology and Pharmacology, University of Strathclyde, Royal College, Glasgow, Scotland, U.K.
Eur Heart J. 1989 Nov;10 Suppl F:73-7. doi: 10.1093/eurheartj/10.suppl_f.73.
The presence of an acid optimum (pH 6) enzyme capable of generating a spasmogenic, vasodilator polypeptide from human plasma kininogen has been demonstrated in dog coronary arteries, veins and in the wall of the left ventricle. This enzyme also cleaved the tripeptide kallikrein substrate Val-Leu-Arg-pNA. Highest amounts were present in the coronary arteries. Gel filtration (Sephacryl S-300) of coronary artery extracts gave a peak for this acid optimum enzyme of 38, 300 +/- 800 Daltons. Its activity was inhibited by pepstatin but not by aprotinin or soya bean trypsin inhibitor. This enzyme, which is similar to a cathepsin, may play a role in the processing of peptide hormones in the heart and coronary vessels.
在犬冠状动脉、静脉及左心室壁中已证实存在一种最适pH为6的酶，该酶能够从人血浆激肽原生成一种致痉挛、血管舒张的多肽。这种酶还能裂解三肽激肽释放酶底物缬氨酸-亮氨酸-精氨酸-对硝基苯胺。冠状动脉中的含量最高。冠状动脉提取物经凝胶过滤（Sephacryl S-300）后，该最适pH为酸性的酶出现一个峰值，分子量为38,300±800道尔顿。其活性被胃蛋白酶抑制剂抑制，但不被抑肽酶或大豆胰蛋白酶抑制剂抑制。这种类似于组织蛋白酶的酶可能在心脏和冠状血管中肽类激素的加工过程中发挥作用。
