Anion activation of angiotensin converting enzyme: dependence on nature of substrate.
Anion activation of angiotensin converting enzyme: dependence on nature of substrate.
复制标题
血管紧张素转换酶的阴离子活化：取决于底物的性质。
DOI：
10.1021/bi00285a021
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发表时间：
1983
期刊：
影响因子：
2.9
通讯作者：
Riordan,JF
中科院分区：
文献类型：
--
作者：
Shapiro,R;Holmquist,B;Riordan,JF
Robert Shapiro、Barton Holmquist 和 James F. Riordan** 摘要：已使用 23 个呋喃丙烯酰基三肽和 3 个苯甲酰基三肽作为底物检查了肺血管紧张素转换酶的阴离子活化。氯化物刺激所有底物的水解至少 24 倍。然而，动力学机制、所需的氯化物量、pH 对活化的影响，以及各种阴离子的相对活化效力，都在很大程度上取决于所使用的底物。已确定了三种底物类别。 I 类底物似乎在 pH 7.5 时通过有序双反应机制水解，其中阴离子必须先于底物结合。 Cl" 的表观活化常数 (KA) 在 pH 7.5 时为 75 至 150 mM，在 pH 9.0 时加倍，在 pH 6.0 时降低至约 3 mM。II 类底物，在
Robert Shapiro, Barton Holmquist, and James F. Riordan** abstract: Anion activation of pulmonary angiotensin con-verting enzyme has been examined by using 23 furanacryloyl-and 3 benzoyl-tripeptides as substrates. Chloride stimulates hydrolysis of all substrates at least 24-fold. However, the kinetic mechanism, the amount of chloride required, and the effect of pH on activation, plus the relative activating potencies of various anions, are all strongly dependent on the substrate employed. Three substrate classes have been identified. Class I substrates appear to be hydrolyzed at pH 7.5 by an ordered bireactant mechanism in which anionmust bind before substrate. The apparent activation constant (KA) for Cl" ranges from 75 to 150 mM at pH 7.5, doubles at pH 9.0, and de-creases to about 3 mM at pH 6.0. Class II substrates, in