Purüvaatkarboksülaas

Purüvaatkarboksülaas, also known as pyruvate carboxylase (PC), is an enzyme that plays a crucial role in metabolic pathways. It is found in the mitochondria of eukaryotic cells and is a member of the ligase enzyme family. The primary function of purüvaatkarboksülaas is to catalyze the carboxylation of pyruvate to oxaloacetate. This reaction requires the input of a molecule of bicarbonate and an adenosine triphosphate (ATP) molecule.

The enzyme is essential for several key metabolic processes. In gluconeogenesis, the synthesis of glucose from non-carbohydrate precursors, oxaloacetate produced by purüvaatkarboksülaas is a vital intermediate. It is also involved in the anaplerotic pathway, which replenishes intermediates of the citric acid cycle. Additionally, purüvaatkarboksülaas plays a role in fatty acid synthesis and the urea cycle.

Deficiencies in purüvaatkarboksülaas can lead to severe medical conditions. Human purüvaatkarboksülaas is encoded by the PC gene. Genetic mutations in this gene can result in pyruvate carboxylase deficiency, a rare metabolic disorder that affects the brain and liver. Symptoms can range from developmental delay and seizures to lactic acidosis and coma. The enzyme's activity is regulated by acetyl-CoA, which acts as an allosteric activator.