Huang F L, Glinsmann W H
Proc Natl Acad Sci U S A. 1975 Aug;72(8):3004-8. doi: 10.1073/pnas.72.8.3004.
Partially purified rabbit skeletal muscle phosphorylase phosphatase (EC 3.1.3.17; phosphoprotein phosphohydrolase) was inactivated when it was incubated with exogenous cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase), cyclic AMP, and ATP-Mg. Subsequent separation of the phosphatase by acrylamide gel electrophoresis or sucrose density centrifugation resulted in reactivation of the enzyme. The phosphatase decreased in molecular weight from approximately 70,000 to 52,000, and a phosphorylated inhibitor with molecular weight of 26,000 was found. Reactivation of phosphatase also occurred when it was incubated with MnCl2 or trypsin. The inhibitor was effective at less than 10(-8) M and was relatively heat stable. Its activity was destroyed by tryptic digestion and by dephosphorylation by a Mn-stimulated phosphatase. These observations support the possibility that phosphorylase phosphatase activity is controlled by cyclic AMP-dependent protein kinase and a Mn-stimulated phosphatase by a reaction involving phosphorylation and dephosphorylation of a protein phosphatase inhibitor.
部分纯化的兔骨骼肌磷酸化酶磷酸酶（EC 3.1.3.17；磷蛋白磷酸水解酶）与外源性环磷酸腺苷依赖性蛋白激酶（EC 2.7.1.37；ATP：蛋白磷酸转移酶）、环磷酸腺苷和ATP-镁一起孵育时会失活。随后通过丙烯酰胺凝胶电泳或蔗糖密度离心分离磷酸酶会导致该酶重新激活。磷酸酶的分子量从约70,000降至52,000，并发现了一种分子量为26,000的磷酸化抑制剂。当磷酸酶与氯化锰或胰蛋白酶一起孵育时也会发生重新激活。该抑制剂在浓度低于10^(-8) M时有效，并且相对耐热。其活性可通过胰蛋白酶消化和锰刺激的磷酸酶去磷酸化而被破坏。这些观察结果支持这样一种可能性，即磷酸化酶磷酸酶活性受环磷酸腺苷依赖性蛋白激酶和锰刺激的磷酸酶的控制，其反应涉及一种蛋白磷酸酶抑制剂的磷酸化和去磷酸化。
