Bollen M, Plana M, Itarte E, Stalmans W
Biochem Biophys Res Commun. 1986 Sep 30;139(3):1033-9. doi: 10.1016/s0006-291x(86)80281-9.
Glycogen synthase a from skeletal muscle was phosphorylated in vitro and then used as substrate for the two major synthase phosphatases from liver. Synthase phosphorylated by cAMP-dependent protein kinase (1.4-1.7 P/subunit) was preferentially activated by the cytosolic S-component; in contrast, progressive phosphorylation by casein kinase-1 (0.9-6.5 P/subunit) yielded substrates that were always better dephosphorylated and activated by the glycogen-bound G-component. We have previously isolated from dog liver several types of synthase b that differ by their need for the S- and/or G-component for prompt activation. After additional phosphorylation by a mixture of synthase kinases the activation of these enzyme preparations required the presence of both components.
骨骼肌中的糖原合酶a在体外被磷酸化，然后用作肝脏中两种主要合酶磷酸酶的底物。由cAMP依赖性蛋白激酶磷酸化的合酶（1.4 - 1.7个磷酸基团/亚基）优先被胞质S组分激活；相反，酪蛋白激酶-1进行的逐步磷酸化（0.9 - 6.5个磷酸基团/亚基）产生的底物总是能被与糖原结合的G组分更好地去磷酸化并激活。我们之前从狗肝脏中分离出了几种合酶b，它们对S和/或G组分快速激活的需求不同。在经过合酶激酶混合物的进一步磷酸化后，这些酶制剂的激活需要两种组分都存在。
