Glycogen Debranching Enzyme (AGL)

Debranching enzymes are responsible for transferring three glucose subunits of glycogen from one parallel chain to another. Afterwards, the donator branch will contain only one glucose residue with alpha-1,6 linkage. This remaining residue is in turn cut by alpha-1,6 glucosidase. This two step process is the general process by which the debranching enzymes "straighten out" glycogen into an unbranched glucose polymer.This enzyme has two independent catalytic activities which occur at different sites on the protein: a 4-alpha-glucotransferase activity and a amylo-1,6-glucosidase activity. Mutations in this gene are associated with glycogen storage disease although a wide range of enzymatic and clinical variability occurs which may be due to tissue-specific alternative splicing.