Reaction: Hydrolysis of (1→6)-α-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin
Other name(s): amylo-1,6-glucosidase; dextrin 6-α-D-glucosidase; amylopectin 1,6-glucosidase; dextrin-1,6-glucosidase; glycogen phosphorylase-limit dextrin α-1,6-glucohydrolase
Systematic name: glycogen phosphorylase-limit dextrin 6-α-glucohydrolase
Comments: This enzyme hydrolyses an unsubstituted (1→6)-α-glucose residue that forms a branch point on an α-(1→4)-linked glucose chain. The enzyme activity found in mammals and yeast is in a polypeptide chain containing two active centres. The other activity is similar to that of EC 188.8.131.52 (4-α-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-α-glucosidase activity can then hydrolyse. Together, these two activities constitute the glycogen debranching system.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9012-47-9
1. Brown, D.H. and Brown, B.I. Enzymes of glycogen debranching: Amylo-1,6-glucosidase (I) and oligo-1,41,4-glucanotransferase (II). Methods Enzymol. 8 (1966) 515-524.
2. Lee, E.Y.C., Carter, J.H., Nielsen, L.D. and Fischer, E.H. Purification and properties of yeast amylo-1,6-glucosidase-oligo-1,4 leads to 1,4-glucantransferase. Biochemistry 9 (1970) 2347-2355. [PMID: 5424210]
3. Nelson, T.E., Kolb, E. and Larner, J. Purification and properties of rabbit muscle amylo-1,6-glucosidase-oligo-1,4-1,4-transferase. Biochemistry 8 (1969) 1419-1428. [PMID: 5805288]