Glycogen Synthase Activity in Adipose Tissue

Methods for Freeze-Clamping and Assay
  • Heidi K. Ortmeyer
Part of the Methods in Molecular Biology™ book series (MIMB, volume 155)


One of the best markers of in vivo insulin-action at insulin sensitive tissues is an increase in glycogen synthase (GS) activity. GS is the rate-limiting enzyme of GS. The activity of glycogen synthase is increased by dephosphorylation, which converts the dependent form (dependent on glucose 6-phosphate [G6P]) to the independent form. GS activity can be increased by an increase in the activities of protein (serine/threonine) phosphatases, which dephosphorylate the enzyme, and/or by a decrease in the activities of protein (serine/threo-nine) kinases, which phosphorylate the enzyme.


Adipose Tissue Homogenization Buffer Euglycemic Hyperinsulinemic Clamp Aluminum Block Place Filter 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Ortmeyer, H. K., Bodkin, N. L., and Hansen, B. C. (1993) Insulin-mediated glycogen synthase activity in muscle of spontaneously insulin-resistant and diabetic rhesus monkeys. Am. J. Physiol. 265, R552–R558.PubMedGoogle Scholar
  2. 2.
    Ortmeyer, H. K., Bodkin, N. L., and Hansen, B. C. (1993) Adipose tissue glycogen synthase activation by in vivo insulin in spontaneously insulin-resistant and Type 2 (non-insulin-dependent) diabetic rhesus monkeys. Diabetologia 36, 200–206.PubMedCrossRefGoogle Scholar
  3. 3.
    Ortmeyer, H. K., Bodkin, N. L., and Hansen, B. C. (1997) Insulin regulates liver glycogen synthase and glycogen phosphorylase activity reciprocally in rhesus monkeys. Am. J. Physiol. 272, E133–E138.PubMedGoogle Scholar
  4. 4.
    Ortmeyer, H. K. and Bodkin, N. L. (1998) Lack of defect in insulin action on hepatic glycogen synthase and phosphorylase in insulin-resistant monkeys. Am. J. Physiol. 274, G1005–G1010.PubMedGoogle Scholar
  5. 5.
    Guinovart, J. J., Salavert, A., Massague, J., Ciudad, C. J., Salsas, E., and Itarte, E. (1979) Glycogen synthase: a new activity ratio assay expressing a high sensitivity to the phosphorylation state. FEBS Lett. 106, 284–288.PubMedCrossRefGoogle Scholar
  6. 6.
    Roach, P. and Larner, J. (1976) Rabbit skeletal muscle glycogen synthase II. Enzyme phosphorylation state and effector concentrations as interacting control parameters. J. Biol. Chem. 251, 1920–1925.PubMedGoogle Scholar
  7. 7.
    Oron, Y. and Larner, J. (1979) A modified rapid filtration assay of glycogen synthase. Anal. Biochem. 94, 409–410.PubMedCrossRefGoogle Scholar
  8. 8.
    Bradford, M. M. (1976) Rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72, 248–254.PubMedCrossRefGoogle Scholar
  9. 9.
    Henderson, P. (1993) Statistical analysis of enzyme kinetic data, in Enzyme Assays: A Practical Approach (Eisenthal, R. and Danson, M., eds.), IRL Press, Oxford, pp. 277–316.Google Scholar
  10. 10.
    Ortmeyer, H. K., Huang, L., Larner, J., and Hansen, B. C. (1998) Insulin unexpectedly increases the glucose 6-phosphate Ka of skeletal muscle glycogen synthase in calorie-restricted monkeys. J. Basic Clin. Physiol. Pharmacol. 9, 309–323.PubMedCrossRefGoogle Scholar

Copyright information

© Humana Press Inc. 2001

Authors and Affiliations

  • Heidi K. Ortmeyer
    • 1
  1. 1.Obesity and Diabetes Research CenterUniversity of Maryland School of MedicineBaltimoreUSA

Personalised recommendations