Inactivation of glycogen synthetase and activation of phosphorylase kinase by muscle adenosine 3',5'-monophosphate-dependent protein kinases.
Inactivation of glycogen synthetase and activation of phosphorylase kinase by muscle adenosine 3',5'-monophosphate-dependent protein kinases.
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肌肉腺苷 3,5-单磷酸依赖性蛋白激酶使糖原合成酶失活并激活磷酸化酶激酶。
DOI：
10.1016/s0021-9258(18)62612-2
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
E. Krebs
中科院分区：
文献类型：
--
作者：
T. Soderling;J. P. Hickenbottom;E. Reimann;F. Hunkeler;D. Walsh;E. Krebs
兔骨骼肌糖原合成酶 I 已被纯化并基本上不含磷酸化酶、磷酸化酶激酶和糖原合成酶激酶。使用纯化的糖原合成酶作为底物，确定来自骨骼肌的两个可分离的腺苷3'，5'-单磷酸（环AMP）依赖性蛋白激酶组分各自催化糖原合成酶I向糖原合成酶D的转化；反应过程中活性的变化与糖原合成酶对磷酸盐的吸收密切相关。这些相同的蛋白激酶组分还催化环 AMP 依赖性磷酸化和磷酸化酶激酶的激活。两种蛋白激酶组分对糖原合成酶和磷酸化酶激酶磷酸化的比活性在纯化过程中同样丰富。通过研究蛋白激酶的热失活、环 AMP 的不稳定、蛋白抑制剂的抑制以及环核苷酸特异性，获得了进一步的证据，证明磷酸化酶激酶磷酸化和糖原合成酶磷酸化是同一酶的共同活性。有证据表明，环 AMP 依赖性蛋白激酶直接作用于糖原合成酶 I，而不是像磷酸化酶激活系统中那样通过第二个激酶起作用。兔骨骼肌糖原合成酶 I 沉积为单峰，ans20，wof 14.3。初步研究表明，该酶可能以由分子量在90,000至100,000之间的亚基组成的四聚体存在。在 I 型转化为 D 型时，该酶每 91,000 克蛋白质掺入 1 摩尔磷酸盐。
Rabbit skeletal muscle glycogen synthetase I has been purified and obtained essentially free of phosphorylase, phosphorylase kinase, and glycogen synthetase kinase. Using the purified glycogen synthetase as substrate, it was determined that two separable adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase fractions from skeletal muscle each catalyze the conversion of glycogen synthetase I to glycogen synthetase D; activity changes during the reaction correlate closely with the uptake of phosphate by glycogen synthetase. These same protein kinase fractions also catalyze the cyclic AMP-dependent phosphorylation and activation of phosphorylase kinase. The specific activities of the two protein kinase fractions towards phosphorylation of glycogen synthetase and phosphorylase kinase were enriched equally during purification. Further evidence that phosphorylase kinase phosphorylation and glycogen synthetase phosphorylation are common activities of the same enzyme was obtained by studying heat inactivation of the protein kinase, destabilization by cyclic AMP, inhibition by a protein inhibitor, and the cyclic nucleotide specificity. Evidence is presented that the cyclic AMP-dependent protein kinase acts directly on glycogen synthetase I and not through a second kinase as occurs in the phosphorylase activation system.Rabbit skeletal muscle glycogen synthetase I sediments as a single peak with ans20,wof 14.3. Preliminary studies indicate that the enzyme probably exists as a tetramer composed of subunits having a molecular weight between 90,000 and 100,000. On conversion of the I form to the D form, the enzyme incorporates 1 mole of phosphate per 91,000 g of protein.