Isolation and characterization of angiotensin converting enzyme from human kidney.
Isolation and characterization of angiotensin converting enzyme from human kidney.
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从人肾中分离和表征血管紧张素转换酶。
DOI：
10.1093/oxfordjournals.jbchem.a133596
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发表时间：
1981
影响因子：
2.7
通讯作者：
Tatsuo Kokubu
中科院分区：
文献类型：
--
作者：
Y. Takada;Kunio Hiwada;Tatsuo Kokubu
血管紧张素转换酶[EC 3.4.15.1]用胰蛋白酶从人肾皮质的膜组分中溶解，并通过deae -纤维素、羟基灰石和DEAE-Sephadex A-50柱层析、制备等电聚焦和Sephadex G-200凝胶过滤纯化至均匀性。酶的最终回收率为13.9%。通过沉淀平衡法估计酶的分子量为199,000。通过十二烷基硫酸盐-聚丙烯酰胺凝胶电泳，得到了还原和变性酶的值为17万。该酶是一种糖蛋白，由一条多肽链组成，等电点为5.10。中性糖占酶重量的13%。纯化后的酶对海马基组氨酸的比活性为96.9 μ mol/min/mg蛋白。该酶对海马基组氨酸的Km值、Kcat值和水解系数分别为2.0 mM、545 s-1和273 mM-1。s - 1。兔抗人肾转化酶抗体对人肺和血清中肾转化酶的抑制作用与对人肾转化酶的抑制作用相同，但对羊、狗和大鼠血清中肾转化酶的抑制作用不同。双免疫扩散分析表明，人肾和肺转化酶在免疫学上是相同的。
Angiotensin converting enzyme [EC 3.4.15.1] was solubilized from the membrane fraction of human kidney cortex using trypsin and purified to homogeneity by DEAE-cellulose, hydroxylapatite and DEAE-Sephadex A-50 column chromatographies, preparative isoelectric focusing, and Sephadex G-200 gel filtration. The final recovery of the enzyme was 13.9%. The molecular weight of the enzyme was estimated to be 199,000 by a sedimentation equilibrium method. A value of 170,000 was obtained for the reduced and denatured enzyme by dodecylsulfate-polyacrylamide gel electrophoresis. The enzyme was a glycoprotein consisting of a single polypeptide chain with an isoelectric point of 5.10. Neutral sugar accounted for 13% per weight of the enzyme. The purified enzyme had a specific activity of 96.9 mumol/min/mg protein for hippurylhistidylleucine. The Km value, Kcat value and hydrolytic coefficient (Kcat/Km) of the enzyme for hippurylhistidylleucine were 2.0 mM, 545 s-1 and 273 mM-1 . s-1, respectively. Rabbit antibody against the human kidney converting enzyme inhibited the activities of the enzymes from human lung and serum as equally as that from human kidney, but not those from sheep, dog, or rat sera. The human kidney and lung converting enzymes were immunologically identical on double immunodiffusion analysis.