Glycogen debranching enzyme

The glycogen debranching enzyme, in humans, is the protein encoded by the <a href="/facts/Gene/e1swwPY6">gene</a> AGL. This enzyme is essential for the <a href="/facts/Glycogenolysis/cMXcNQKE">breakdown</a> of <a href="/facts/Glycogen/kWa8fPFE">glycogen</a>, which serves as a store of glucose in the body. It has separate glucosyltransferase and glucosidase activities.
Together with <a href="/facts/Phosphorylase/WYudaRzR">phosphorylases</a>, the enzyme mobilize <a href="/facts/Glucose/oUSkoLCD">glucose</a> 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 <a href="/facts/Liver/Rtp4Fk2b">liver</a>, by various hormones including <a href="/facts/Insulin/oXG0myt1">insulin</a> and <a href="/facts/Glucagon/NVEnH03n">glucagon</a>, to maintain a homeostatic balance of blood-glucose levels. When glycogen breakdown is compromised by mutations in the glycogen debranching enzyme, metabolic diseases such as <a href="/facts/Glycogen_storage_disease_type_III/vsfdXB87">Glycogen storage disease type III</a> can result.
The two steps of glycogen breakdown, glucosyltransferase and glucosidase, are performed by a single <a href="/facts/Enzyme/DSI1Fh7y">enzyme</a> in mammals, yeast, and some bacteria, but by two distinct enzymes in <a href="/facts/E._coli/nR4Gvl56">E. coli</a> and other bacteria, complicating nomenclature. Proteins that catalyze both functions are referred to as glycogen debranching enzymes (GDEs). When glucosyltransferase and glucosidase are catalyzed by distinct enzymes, glycogen debranching enzyme usually refers to the glucosidase <a href="/facts/Enzyme/DSI1Fh7y">enzyme</a>. In some literature, an enzyme capable only of glucosidase is referred to as a debranching enzyme.

Glycogen debranching enzyme open-in-new

Glycogen debranching enzyme