2-Phosphoglyceric acid

2-Phosphoglyceric acid (2-PGA) is a biochemical compound that plays a critical role in the glycolysis metabolic pathway. It is a monophosphoric ester of glyceric acid, serving as an intermediate in the transformation of 3-phosphoglyceric acid (3-PGA) to phosphoenolpyruvate (PEP), a process catalyzed by the enzyme enolase.

Structure and Properties[edit | edit source]

2-Phosphoglyceric acid consists of a three-carbon backbone derived from glyceric acid, with a phosphate group esterified to the second carbon atom. This structural configuration is crucial for its role in metabolism, particularly in the enolase-catalyzed dehydration step in glycolysis, where it is converted to phosphoenolpyruvate by the removal of a water molecule.

The molecular formula of 2-phosphoglyceric acid is C3H7O7P, and it has a molar mass of 186.06 g/mol. It is a highly polar molecule due to the presence of the phosphate group, which also imparts a negative charge at physiological pH, contributing to its solubility in water.

Role in Glycolysis[edit | edit source]

In the glycolytic pathway, 2-PGA is synthesized from 3-phosphoglyceric acid by the action of the enzyme phosphoglycerate mutase. This reaction involves a shift of the phosphate group from the third carbon to the second carbon, forming 2-phosphoglyceric acid. Subsequently, 2-PGA is converted into phosphoenolpyruvate by the enzyme enolase. This step is crucial for the subsequent production of ATP (adenosine triphosphate), the universal energy currency of the cell, in the final steps of glycolysis.

Clinical Significance[edit | edit source]

Alterations in the levels of 2-phosphoglyceric acid can indicate metabolic disturbances or diseases. For instance, deficiencies in the enzymes responsible for its metabolism, such as enolase, can lead to a buildup of 2-PGA, which may affect the efficiency of glycolysis and energy production in cells. Research into the regulation of 2-PGA and its metabolic pathway components may provide insights into conditions such as cancer, where glycolysis is often upregulated.