RAT INTESTINAL ANGIOTENSIN-CONVERTING ENZYME - PURIFICATION, PROPERTIES, EXPRESSION, AND FUNCTION
RAT INTESTINAL ANGIOTENSIN-CONVERTING ENZYME - PURIFICATION, PROPERTIES, EXPRESSION, AND FUNCTION
复制标题
DOI：
10.1152/ajpgi.1992.263.4.g466
复制
发表时间：
1992-10-01
影响因子：
--
通讯作者：
KIM, YS
中科院分区：
文献类型：
--
作者：
ERICKSON, RH;SUZUKI, Y;KIM, YS
从大鼠肠粘膜的总细胞膜部分纯化血管紧张素转换酶[ACE（肽基-二肽酶A，EC 3.4.15.1）]。用赖诺普利-琼脂糖凝胶亲和层析和凝胶过滤后，达到4,500倍的纯化。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳判断最终制剂是均匀的，表观分子量为160，000。纯化的蛋白质是含12% N-连接碳水化合物的糖酶。纯化的ACE以苯甲酰-Gly-His-Leu为底物，比活力为65 U/mg蛋白。动力学分析表明，该酶具有最大的速度与底物含有脯氨酸的COOH-末端。抑制剂研究表明，该酶是一种金属蛋白。沿着小肠的近端-远端轴，ACE活性在近端至中间部分最显著，朝向远端降低。ACE mRNA和蛋白也观察到这种模式，表明ACE表达在mRNA水平上受到控制。通过一段肠空肠灌注苯甲酰-甘氨酸-组氨酸-亮氨酸证明ACE是一种重要的肠二肽羧肽酶，参与饲料肽的消化和同化。
Angiotensin-converting enzyme [ACE (peptidyl-dipeptidase A, EC 3.4.15.1)] was purified from a total cell membrane fraction of rat intestinal mucosa. A 4,500-fold purification was achieved after affinity chromatography with lisinopril-Sepharose and gel filtration. The final preparation was judged to be homogenous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 160,000. The purified protein is a glycoenzyme containing 12% N-linked carbohydrate. Purified ACE had a specific activity of 65 U/mg protein with benzoyl-Gly-His-Leu as substrate. A kinetic analysis showed that the enzyme had the maximal velocity with substrates containing proline at the COOH-terminal end. Inhibitor studies indicated that the enzyme is a metalloprotein. Along the proximal-distal axis of the small intestine, ACE activity is most predominant in the proximal to middle portions, decreasing toward the distal end. This pattern was also observed for ACE mRNA and protein, suggesting that ACE expression is controlled at the level of mRNA. Perfusion of benzoyl-Gly-His-Leu in vivo through a segment of intestinal jejunum demonstrated that ACE is an important intestinal dipeptidyl carboxypeptidase, participating in the digestion and assimilation of dietary peptides.