pyruvate carboxylase

pyruvate carboxylase

[pī′ro̅o̅·vāt kär·bok′sə·lās]

an enzyme that catalyzes the irreversible carboxylation of pyruvate, a reaction necessary for gluconeogenesis from lactate or amino acids forming pyruvate and also providing four-carbon compounds for the citric acid cycle. The enzyme is a mitochondrial protein occurring in liver but not in muscle. Deficiency of the enzyme, an autosomal-recessive trait, causes severe psychomotor retardation and lactic acidosis in infants. There is a particularly severe, rapidly fatal form, in which hyperammonemia, citrullinemia, and excess of lysine in the blood are also present.

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pyruvate

a salt, ester or anion of pyruvic acid. The term is used interchangeably with pyruvic acid. Pyruvate is the end product of glycolysis and may be metabolized in the body to lactate or to acetyl CoA. In yeast it is metabolized to ethanol.

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pyruvate carboxylase

an enzyme concerned in the conversion of pyruvate to oxaloacetic acid.

pyruvate dehydrogenase

actively concerned in the decarboxylation of pyruvate to acetyl CoA and CO₂.

pyruvate kinase

a glycolytic pathway enzyme (called also PK) which catalyzes the formation of pyruvate from phosphoenolpyruvate (PEP). A deficiency of the enzyme is a hereditary defect in humans and occurs also in Beagle and Basenji dogs, causing a familial nonspherocytic anemia.

pyruvate transaminase

see alanine aminotransferase.