Glycogen synthase regulating glycogen/glucose levels and is activated by dephosphorylation. In humans, there are two paralogous isozymes of glycogen synthase: The liver enzyme expression is restricted to the liver, whereas the muscle enzyme is widely expressed. Liver glycogen serves as a storage pool to maintain the blood glucose level during fasting, whereas muscle glycogen synthesis accounts for disposal of up to 90% of ingested glucose. The role of muscle glycogen is as a reserve to provide energy during bursts of activity. Meanwhile, the muscle isozyme plays a major role in the cellular response to long-term adaptation to hypoxia. Notably, hypoxia only induces
Glycogen debranching enzyme glucoamylase, respectively. Their active sites are selective towards the respective substrates, ensuring proper activation of GDE. Besides the active sites GDE have additional binding sites for glycogen, which are important for its recruitment to glycogen. Mapping the disease-causing mutations onto the GDE structure provided insights into glycogen storage disease type III. The official name for the gene is "amylo- α- 1,6- glucosidase, 4- α- glucanotransferase", with the official symbol AGL. AGL is an autosomal gene found on chromosome lp21. The AGL gene provides instructions for making several different versions, known as isoforms, of the glycogen debranching enzyme. These isoforms vary