Glycogen debranching enzyme Glycogen debranching enzyme A debranching enzyme is a molecule that helps facilitate the breakdown of glycogen, which serves as a store of glucose in the body, through glucosyltransferase and glucosidase activity. Together with phosphorylases, debranching enzymes mobilize glucose reserves from glycogen deposits in the muscles and liver. This constitutes a major source of energy reserves in most organisms. Glycogen breakdown is highly regulated in the body, especially in the liver, by various hormones including insulin and glucagon, to maintain a homeostatic balance of blood-glucose levels. When glycogen breakdown is compromised by mutations in the glycogen debranching enzyme, metabolic diseases such
Glycogen phosphorylase concentration, as the liver acts as a glucose exporter. In essence, liver phosphorylase is responsive to glucose, which causes a very responsive transition from the R to T form, inactivating it; furthermore, liver phosphorylase is insensitive to AMP. Glycogen phosphorylase was the first allosteric enzyme to be discovered. This accomplishment was one of many landmark achievements made by Carl and Gerty Cori. In 1943, with the help of Arda Green, the pair illustrated that glycogen phosphorylase existed in either the or b forms depending on its phosphorylation state, as well as in the R or T states based on the