pH dependence of salt activation of human leukocyte elastase.
pH dependence of salt activation of human leukocyte elastase.
复制标题
人白细胞弹性蛋白酶的盐激活的 pH 依赖性。
DOI：
10.1016/0003-9861(84)90619-2
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发表时间：
1984
影响因子：
3.9
通讯作者：
M. Yamada
中科院分区：
文献类型：
--
作者：
G. Oshima;K. Akashi;M. Yamada
研究了pH值对盐刺激对人白细胞弹性蛋白酶水解三种底物速率的影响。该酶在 pH 10.5、8.0–8.5 和 9.5 时最活跃，可水解异硫氰酸荧光素标记的 S-羧甲基化牛血清白蛋白 (FITC-CM-BSA)、琥珀酰-l-Ala-l-Pro-l-Ala-7-甲基-香豆酰-4-酰胺 (Suc-APA-MCA) 和琥珀酰-l-Ala3-p-硝基苯胺（Suc-Ala3-pNA）分别在没有 NaCl 的情况下。在所有测试的 Suc-Ala3-pNA 水解测试的 pH 值下，该酶均被 0.5mNaCl 类似地激活，但对于 FITC-CM-BSA 和 Suc-APA-MCA 的水解，分别在中性和碱性 pH 值下激活酶更多。因此，在存在 0.5mNaCl 的情况下，该酶分别在 FITC-CM-BSA 和 Suc-APA-MCA 的 pH 8.0 和 10.0 时最具活性。相比之下，猪胰腺弹性蛋白酶的蛋白水解活性在一定程度上被0.5mNaCl抑制。
The effects of pH on salt stimulation of the rates of hydrolysis of three substrates by human leukocyte elastase were studied. The enzyme was most active at pH 10.5, 8.0–8.5, and 9.5 for the hydrolyses of fluorescein isothiocyanate-labeledS-carboxymethylated bovine serum albumin (FITC-CM-BSA), succinyl-l-Ala-l-Pro-l-Ala-7-methyl-coumaryl-4-amide (Suc-APA-MCA), and succinyl-l-Ala3-p-nitroanilide (Suc-Ala3-pNA), respectively, in the absence of NaCl. The enzyme was activated by 0.5mNaCl similarly at all pHs tested for the hydrolysis of Suc-Ala3-pNA, but more at neutral and alkaline pH values, respectively, for the hydrolyses of FITC-CM-BSA and Suc-APA-MCA. Thus, in the presence of 0.5mNaCl, the enzyme was most active at pH 8.0 and 10.0 with FITC-CM-BSA and Suc-APA-MCA, respectively. In contrast, the proteolytic activity of porcine pancreatic elastase was somewhat inhibited by 0.5mNaCl.