Uridine diphosphate glucose breakdown is mediated by a unique enzyme activated by fructose 2,6-bisphosphate in Solanum tuberosum
AUTOR(ES)
Gibson, Donna M.
RESUMO
In the presence of inorganic phosphate, uridine 5′-diphosphate glucose (UDPG) is specifically hydrolyzed to glucose 1-phosphate and UDP by a unique enzyme, UDPG phosphorylase. The activity of the enzyme was maximally stimulated by fructose 2,6-bisphosphate, a regulatory metabolite recently discovered in both plants and animals, and by 2-phosphoglyceric acid. At 1 μM, fructose 2,6-bisphosphate stimulated UDPG phosphorolysis 10-fold, whereas 2-phosphoglyceric acid was required at higher concentrations (100 μM) to produce a similar effect. Fructose 2,6-bisphosphate appears to increase the affinity of the enzyme for inorganic phosphate, with a change in Km from 1.6 mM to 0.3 mM. The results suggest that fructose 2,6-bisphosphate participates in the regulation of other pathways of carbohydrate metabolism in addition to playing its recognized role in glycolysis and gluconeogenesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=393851Documentos Relacionados
- Fructose 2,6-Bisphosphate Inhibition of Phosphoglucomutase 1
- Fructose 2,6-Bisphosphate and Plant Carbohydrate Metabolism
- Fructose 2,6-bisphosphate and germination of fungal spores
- Fructose 2,6-bisphosphate and germination of fungal spores
- Control of liver 6-phosphofructokinase by fructose 2,6-bisphosphate and other effectors.
