Nakai C, Glinsmann W
Mol Cell Biochem. 1977 Apr 12;15(2):133-9. doi: 10.1007/BF01793335.
A heat-and acid-stable protein inhibitor of phosphorylase phosphatase is present in a highly purified preparation of protein inhibitor of cyclic AMP-dependent protein kinase from rabbit skeletal muscle. Although these two inhibitors have strikingly similar properties to each other, such as sensitivity to trypsin and behavior on gel permeation chromatography, they can be separated by polyacrylamide disc gel electrophoresis. This indicates that the phosphatase-inhibitory and kinase-inhibitory activities reside with different protein species. The inhibition of both the enzymes is not altered by incubating the inhibitor preparation with a general phosphoprotein phosphatase, with phosvitin kinase, or with cyclic AMP-dependent protein kinase. Inhibition of phosphorylase phosphatase is of a non-competitive type supporting the idea that the phosphatase inhibitor is not an alternative substrate for the enzyme. Inhibition of phosphatase activity is selective in that it does no occur when phosphorylated histone or phosphorylated protamine are used as substrates.
在从兔骨骼肌中高度纯化的环磷酸腺苷依赖性蛋白激酶的蛋白抑制剂制剂中，存在一种对热和酸稳定的磷酸化酶磷酸酶蛋白抑制剂。尽管这两种抑制剂彼此具有惊人的相似特性，例如对胰蛋白酶的敏感性和凝胶渗透色谱行为，但它们可以通过聚丙烯酰胺圆盘凝胶电泳分离。这表明磷酸酶抑制活性和激酶抑制活性存在于不同的蛋白质种类中。用通用磷酸蛋白磷酸酶、卵黄高磷蛋白激酶或环磷酸腺苷依赖性蛋白激酶孵育抑制剂制剂，不会改变对这两种酶的抑制作用。磷酸化酶磷酸酶的抑制是非竞争性的，这支持了磷酸酶抑制剂不是该酶替代底物的观点。磷酸酶活性的抑制具有选择性，因为当使用磷酸化组蛋白或磷酸化鱼精蛋白作为底物时不会发生抑制。
