The binding of zinc to angiotensin-converting enzyme.
The binding of zinc to angiotensin-converting enzyme.
复制标题
锌与血管紧张素转换酶的结合。
DOI：
10.1016/0003-9861(88)90137-3
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发表时间：
1988
影响因子：
3.9
通讯作者：
Wilson,IB
中科院分区：
文献类型：
--
作者：
Schullek,JR;Wilson,IB
用氯化锌-氨三乙酸（NTA）缓冲液测定了锌离子与血管紧张素转换酶（ACE）解离的平衡常数。解离常数为6.4 × 10− 10 m。平衡时活性酶的分数是独立的底物的存在下，这表明，马尿酰组氨酰亮氨酸结合同样好的全酶和脱辅基酶。测得锌从ACE中解离的速率常数为0.68 min− 1（游离酶）;酶底物复合物的速率常数约为0.18 min−1。锌离子与ACE的结合速度非常快，速率常数为1.06 × 109 m − 1 min −1。乙二胺四乙酸（EDTA）和NTA快速从ACE中去除锌，速率常数分别为1.27 × 103和2.2 × 103 m − 1 min −1。NTA与ACE反应的平衡常数测得为4.6 × 10− 2，计算出EDTA的平衡常数为3.8 × 103。
The equilibrium constant for the dissociation of zinc ion from angiotensin-converting enzyme (ACE) was measured using zinc ion buffers of zinc chloride and nitrilotriacetic acid (NTA). The dissociation constant is 6.4 × 10−10m. The fraction of active enzyme at equilibrium is independent of the presence of substrate which indicates that hippurylhistidylleucine binds equally well to the holoenzyme and apoenzyme. The rate constant for the dissociation of zinc from ACE was measured as 0.68 min−1for the free enzyme; the rate constant for the enzyme substrate complex was roughly 0.18 min−1. The association of zinc ion and ACE is very fast; the rate constant is 1.06 × 109m−1min−1. Ethylenediaminetetraacetic acid (EDTA) and NTA rapidly remove zinc from ACE with rate constants of 1.27 × 103and 2.2 × 103m−1min−1. The equilibrium constant for the reaction of NTA with ACE was measured as 4.6 × 10−2and was calculated for EDTA as 3.8 × 103.