diphosphateglucose

Diphosphoglucose, also known as glucose-1,6-bisphosphate, is a phosphorylated form of glucose that plays a role in carbohydrate metabolism. It is an intermediate in glycolysis and gluconeogenesis. The molecule consists of a glucose unit with two phosphate groups attached. One phosphate group is linked to the oxygen at the first carbon atom (C1) of the glucose molecule, forming a phosphate ester. The second phosphate group is attached to the oxygen at the sixth carbon atom (C6) of the glucose molecule, also forming a phosphate ester.

In biological systems, diphosphoglucose is formed from glucose-6-phosphate and ATP through the action of phosphoglucomutase and ATP. It is then converted to fructose-1,6-bisphosphate, a key regulatory step in glycolysis, catalyzed by phosphofructokinase. Conversely, during gluconeogenesis, fructose-1,6-bisphosphate is dephosphorylated to fructose-6-phosphate, and then diphosphoglucose can be formed from glucose-6-phosphate. The interconversion of glucose-6-phosphate and glucose-1-phosphate, catalyzed by phosphoglucomutase, is a crucial step in these pathways, and diphosphoglucose acts as a necessary intermediate in this isomerization. Its presence and regulation are vital for maintaining cellular energy homeostasis and the supply of glucose for metabolic processes.