Frog liver glycogen synthase. In vitro and in vivo interconversions between I and D forms

Comp Biochem Physiol B. 1978;59(4):277-84. doi: 10.1016/0305-0491(78)90002-0.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Glycogen Synthase / metabolism*
  • Isoenzymes / metabolism*
  • Kinetics
  • Liver / enzymology*
  • Rana ridibunda

Substances

  • Isoenzymes
  • Glycogen Synthase