Pyruvate dehydrogenase phosphatase

Pyruvate dehydrogenase phosphatase (PDP) is an enzyme that plays a crucial role in the metabolism of carbohydrates. It is responsible for the dephosphorylation of pyruvate dehydrogenase, a key enzyme in the citric acid cycle, which is a central metabolic pathway in all aerobic organisms.

Function

PDP is a regulatory enzyme that activates the pyruvate dehydrogenase complex (PDC) by reversing the phosphorylation of pyruvate dehydrogenase. This process is essential for the production of acetyl-CoA, a molecule that is integral to the citric acid cycle and the synthesis of fatty acids and cholesterol.

Structure

PDP is a heterodimer composed of two subunits: a regulatory subunit and a catalytic subunit. The regulatory subunit is responsible for binding to the PDC, while the catalytic subunit carries out the dephosphorylation reaction.

Clinical significance

Deficiencies in PDP can lead to a buildup of pyruvate and lactic acid in the body, resulting in a condition known as lactic acidosis. This can cause a variety of symptoms, including muscle weakness, fatigue, and rapid breathing. In severe cases, it can be life-threatening.

See also

• Pyruvate dehydrogenase complex
• Citric acid cycle
• Lactic acidosis