Activation of bovine brain calmodulin-dependent protein phosphatase by limited trypsinization.
Activation of bovine brain calmodulin-dependent protein phosphatase by limited trypsinization.
复制标题
通过有限的胰蛋白酶作用激活牛脑钙调蛋白依赖性蛋白磷酸酶。
DOI：
10.1021/bi00300a027
复制
发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
W. Cheung
中科院分区：
文献类型：
--
作者：
E. Tallant;W. Cheung
从牛脑中分离的钙调蛋白依赖性蛋白磷酸酶[Tallant，E.A.，& Cheung，W.Y.（1983）Biochemistry 22，3630-3635]被有限的胰蛋白酶消化刺激至与钙调蛋白相同的活性水平。长时间的胰蛋白酶消化导致磷酸酶活性的逐渐丧失，这一过程在Ca 2+的存在下延迟，并且在钙调蛋白的存在下甚至更延迟。胰蛋白酶化磷酸酶，当完全激活时，具有60 000的分子量，并由43 000和16 000道尔顿的两种蛋白质组成。胰蛋白酶化降低了酪蛋白磷酸酶的Km从10.8到1.2 microM，并增加了Vmax从4.9到30.9 nmol（mg蛋白质）-1 min-1。蛋白水解的酶对钙调素不敏感，并且不结合钙调素-琼脂糖亲和柱。然而，它是由Ca 2+刺激，需要0.4 μ M的Ca 2+的半最大激活。天然和胰蛋白酶化的磷酸酶刺激Mn ~（2+）的水平大大高于Ca ~（2+）。
A calmodulin-dependent protein phosphatase isolated from bovine brain [Tallant, E.A., & Cheung, W.Y. (1983) Biochemistry 22, 3630-3635] is stimulated by limited trypsinization to the same activity level as that by calmodulin. Prolonged trypsinization caused gradual loss of phosphatase activity, a process retarded in the presence of Ca2+, and even more in the presence of calmodulin. Trypsinized phosphatase, when fully activated, had a molecular weight of 60 000 and was composed of two protein species of 43 000 and 16 000 daltons. Trypsinization decreased the Km of phosphatase for casein from 10.8 to 1.2 microM and increased the Vmax from 4.9 to 30.9 nmol (mg of protein)-1 min-1. The proteolyzed enzyme was insensitive to calmodulin and did not bind to a calmodulin-Sepharose affinity column. It was, however, stimulated by Ca2+, requiring 0.4 microM Ca2+ for half-maximal activation. Both native and trypsinized phosphatase were stimulated by Mn2+ to a level considerably higher than that by Ca2+.
Ca2 依赖性肌球蛋白轻链激酶从骨骼肌转化为 Ca2 不依赖性形式。
DOI：
10.1016/0006-291x(83)91206-8
发表时间：
1983
影响因子：
3.1
作者：
Srivastava,S;Hartshorne,DJ
通讯作者：
Hartshorne,DJ
影响因子：
2.9
作者：
Walsh,MP;Dabrowska,R;Hinkins,S;Hartshorne,DJ
通讯作者：
Hartshorne,DJ