title: Frog liver glycogen synthase. In vitro and in vivo interconversions between I and D forms.
abstract: 1. Frog liver has enzymatic systems able to interconvert glycogen synthase. 2. D to I conversion is achieved in vitro by incubation at 30 degrees C. ATP, ADP, inorganic phosphate and glycogen are inhibitors of this conversion, whereas glucose-6-P and Mg2+ stimulate it. 3. I to D conversion in vitro depends on ATP-Mg2+. Cyclic-AMP activates this conversion, while glucose-6-P inhibits it. 4. Injection of glucose, ribose, mannose, fructose, galactose, and cortisone into frogs increase liver percentage of I activity. 5. Glucagon and adrenaline decrease percentage of I activity.
mesh_terms: D000818:Animals; D006006:Glycogen Synthase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D011895:Rana ridibunda
chemical_list: D007527:Isoenzymes; D006006:Glycogen Synthase