Glucose 1-phosphate

Reactions of α-glucose 1-phosphate

Catabolic

In glycogenolysis, it is the direct product of the reaction in which glycogen phosphorylase cleaves off a molecule of glucose from a greater glycogen structure. A deficiency of muscle glycogen phosphorylase is known as glycogen storage disease type V (McArdle Disease).

To be utilized in cellular catabolism it must first be converted to glucose 6-phosphate by the enzyme phosphoglucomutase in a free equilibrium. One reason that cells form glucose 1-phosphate instead of glucose during glycogen breakdown is that the very polar phosphorylated glucose cannot leave the cell membrane and so is marked for intracellular catabolism. Phosphoglucomutase-1 deficiency is known as glycogen storage disease type 14 (GSD XIV).

Anabolic

In glycogenesis, free glucose 1-phosphate can also react with UTP to form UDP-glucose, by using the enzyme UDP-glucose pyrophosphorylase. It can then return to the greater glycogen structure via glycogen synthase.

β-Glucose 1-phosphate

β-Glucose 1-phosphate is found in some microbes. It is produced by inverting α-glucan phosphorylases including maltose phosphorylase, kojibiose phosphorylase and trehalose phosphorylase and is then converted into glucose 6-phosphate by β-phosphoglucomutase.

References

References

1. Pelley, John W.. (2012-01-01). "8 - Gluconeogenesis and Glycogen Metabolism". W.B. Saunders.
2. Isselbacher, Kurt J.. (1965-01-01). "Galactose-1-phosphate Uridyl Transferase". Academic Press.
3. Bergmeyer, Hans-Ulrich. (1965-01-01). "d-Glucose-1-phosphate". Academic Press.
4. [http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Expert=711 Orphanet: Glycogen storage disease due to phosphoglucomutase deficiency]
5. Blanco, Antonio. (2017-01-01). "Chapter 19 - Integration and Regulation of Metabolism". Academic Press.