Radiochemical Assessment of Glycogen Synthase Enzyme Activity in Animal Tissue

Glycogen is an important metabolite to many eukaryotic cells, integral to energy storage and quick energy release. The building of the molecule is dependent on glycogen synthase, a highly regulated enzyme with the primary function of facilitating the sequential attachment of glucose units in a growing glycogen polymer. This enzyme is allosterically activated by glucose-6-phosphate and inhibited at multiple sites by phosphorylation. Knowledge of glycogen synthase enzymatic activity is a key component of understanding glycogen metabolism, muscle energy levels, and metabolic disorders such as diabetes and glycogen storage diseases. Described here is a highly sensitive and effective method of determining the activity of glycogen synthase in animal muscle tissue by measuring the amount of integrated glucose, from radio-labeled [14C]-UDP-glucose, into glycogen molecules. This procedure utilizes radioactive ¹⁴C and will require the proper authorization and lab space for use and disposal. This procedure will also require access to a liquid scintillation counter.