Cytosolic Ca2+-dependent neutral proteinases from rabbit liver: activation of the proenzymes by Ca2+ and substrate.
Cytosolic Ca2+-dependent neutral proteinases from rabbit liver: activation of the proenzymes by Ca2+ and substrate.
复制标题
来自兔肝的胞质 Ca2 依赖性中性蛋白酶：Ca2 和底物激活酶原。
DOI：
10.1073/pnas.81.1.53
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发表时间：
1984
影响因子：
11.1
通讯作者：
B. Horecker
中科院分区：
文献类型：
--
作者：
S. Pontremoli;E. Melloni;F. Salamino;B. Sparatore;M. Michetti;B. Horecker
从兔肝脏中分离出两种分子大小不同的中性 Ca2+ 依赖性蛋白酶。两者都以无活性酶原的形式回收，在没有底物的情况下，可以通过高浓度 (0.1-1.0 mM) Ca2+ 转化为活性形式，或者在存在蛋白质底物的情况下，通过低浓度 (1-5 µM) Ca2+ 转化为活性酶原。激活的蛋白酶仅需要 1-5 microM Ca2+ 即可获得最大活性。水解的底物是变性的球蛋白、球蛋白、酪蛋白，以及较小程度的几种细胞外蛋白质；测试的几种细胞内胞质酶没有观察到消化。只有那些充当底物的蛋白质才能够促进酶原转化为活性低Ca2+需求蛋白酶。
Two neutral Ca2+-dependent proteinases, differing in molecular size, have been isolated from rabbit liver. Both are recovered as inactive proenzymes that can be converted to the active forms by high (0.1-1.0 mM) concentrations of Ca2+ in the absence of substrate or, in the presence of a protein substrate, by low (1-5 microM) concentrations of Ca2+. The activated proteinases required only 1-5 microM Ca2+ for maximal activity. Substrates hydrolyzed were denatured globin, globin, casein, and to a lesser extent, several extracellular proteins; no digestion was observed with several intracellular cytosolic enzymes tested. Only those proteins that served as substrates were capable of promoting conversion of the proenzymes to the active low-Ca2+-requiring proteinases.