2fosfoglycer

2-Phosphoglycerate is a phosphorylated three-carbon metabolite that appears in glycolysis as an intermediate between 3-phosphoglycerate and phosphoenolpyruvate. It is commonly referred to as 2-phosphoglycerate (2-PG) or 2-phosphoglyceric acid. The molecule is a glycerate with a phosphate group attached to the second carbon, and in cellular metabolism it is usually the L-enantiomer that participates in enzymatic reactions.

In glycolysis, 3-phosphoglycerate is converted to 2-phosphoglycerate by the enzyme phosphoglycerate mutase, which moves the phosphate group within the molecule. The 2-phosphoglycerate is then dehydrated by enolase to yield phosphoenolpyruvate (PEP), a high-energy intermediate that is subsequently converted to pyruvate by pyruvate kinase, producing ATP in the process. The conversion from 2-PG to PEP is a key step that helps couple glycolysis to energy extraction from glucose. In gluconeogenesis, the reverse sequence can operate to regenerate 3-phosphoglycerate from 2-phosphoglycerate through the coordinated action of the corresponding enzymes.

Biochemically, 2-phosphoglycerate serves as a substrate for glycolytic enzymes and as a linkage point between upstream sugar metabolism and downstream pyruvate formation. Its levels reflect the flux through glycolysis and can be influenced by cellular energy state and allosteric regulation of the pathway. Related metabolites include 3-phosphoglycerate and phosphoenolpyruvate, which define the surrounding steps of the pathway.