Amylo-alpha-1,6-glucosidase and 4-alpha-glucanotransferase (AGL) (AGL)

Amylo-alpha-1,6-glucosidase and 4-alpha-glucanotransferase (AGL) is a multifunctional enzyme essential for the complete breakdown of glycogen, a process known as glycogenolysis (Wikipedia, 2024; MedlinePlus, 2024). It possesses two distinct catalytic activities: a 4-alpha-glucanotransferase activity that relocates glucose residues and an amylo-alpha-1,6-glucosidase activity that hydrolyzes the branch points of the glycogen polymer (UniProt, 2024; NIH, 2024). This dual functionality allows the enzyme to work in tandem with glycogen phosphorylase to mobilize glucose from stored glycogen in the liver and muscles (Wikipedia, 2024; MedlinePlus, 2024). Mutations in the AGL gene result in Glycogen Storage Disease Type III (GSD III), also known as Cori or Forbes disease, which is characterized by the accumulation of abnormal glycogen and symptoms such as hepatomegaly, hypoglycemia, and progressive myopathy (ResearchGate, 2024; MedlinePlus, 2024). Beyond its metabolic role, AGL has recently been identified as a tumor suppressor in bladder and non-small cell lung cancers, where its loss leads to increased hyaluronic acid synthesis and tumor growth (NIH, 2018; Oncotarget, 2018). While there are currently no approved drugs that directly restore AGL function, therapeutic strategies under investigation include gene therapy and enzyme replacement, while inhibitors of downstream pathways like 4-methylumbelliferone are being explored for AGL-deficient malignancies (NIH, 2023; AACR, 2018).

Other names

Glycogen debranching enzymeGDEAmylo-1,6-glucosidase4-alpha-glucanotransferaseCori disease enzymeForbes disease enzyme

Alpha-glucosidase inhibition; Enzyme replacement therapy (experimental); Gene therapy (experimental)