Specificity of Debranching Enzymes

THE debranching enzymes are a most important group because, with the amylases and phosphorylases, they completely degrade starch and glycogen to the monosaccharide level. Some of the earlier preparations of debranching enzymes were not homogeneous and their use led to erroneous conclusions about their specificity. These views were later qualified by studies using more highly purified preparations. For example, some preparations of yeast isoamylase hydrolysed α-1,6-D-glucosidic linkages in both glycogen and oligosaccharide α-dextrins1, but the latter activity is now no longer ascribed to isoamylase2.