1,4-alpha-oligoglucan phosphorylase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 1,4-alpha-D-glucosyl(n) + phosphate = 1,4-alpha-D-glucosyl(n-1) + alpha-D-glucose 1-phosphate. The name should be qualified in each instance by adding the name of the natural substrate, e.g. maltodextrin phosphorylase, starch phosphorylase, glycogen phosphorylase. [EC:2.4.1.1]

1,4-alpha-oligoglucan phosphorylase activity catalyzes the reversible phosphorolysis of alpha-1,4-glucans, such as starch and glycogen, to release glucose-1-phosphate. This reaction is essential for glucose mobilization from storage polysaccharides. The enzyme utilizes inorganic phosphate (Pi) to cleave the alpha-1,4-glycosidic bonds at the non-reducing end of the glucan chain. The reaction proceeds through a two-step mechanism: first, the enzyme binds to the substrate glucan and Pi, forming a complex. Then, the enzyme cleaves the glycosidic bond, releasing glucose-1-phosphate and leaving the glucan chain one glucose unit shorter. This reaction is reversible, meaning that the enzyme can also catalyze the synthesis of glycogen or starch from glucose-1-phosphate. The direction of the reaction is determined by the relative concentrations of the substrates and products. In addition to its role in glucose metabolism, 1,4-alpha-oligoglucan phosphorylase activity also plays a role in other cellular processes, such as the regulation of glycogen synthesis and degradation, and the control of gene expression.'
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Proteins (3)

Compounds (29)