High Quality Content by WIKIPEDIA articles! A debranching enzyme is a molecule that helps facilitate the breakdown of glycogen 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. When glycogen breakdown is compromised by mutations in the glycogen debranching enzyme, metabolic diseases such as Glycogen storage disease type III can result.