pyruvate

A salt or ester of pyruvic acid.

- active p. an intermediate formed in the oxidative decarboxylation of p.. Cf.:p. dehydrogenase (lipoamide). SYN: α-lactyl-thiamin pyrophosphate.

- p. carboxylase ligase catalyzing reaction of ATP, p., and HCO₃²⁻, to form ADP, orthophosphate, and oxaloacetate; biotin and acetyl-CoA are involved; an absence of this enzyme results in neuronal loss in the cerebral cortex, leading to mental retardation.

- p. decarboxylase α-carboxylase; α-ketoacid carboxylase; a thiamin-pyrophosphate–dependent carboxylase of yeast catalyzing decarboxylation of a 2-oxoacid ( e.g., p.) to an aldehyde ( e.g., acetaldehyde) without oxidoreduction and without lipoamide, in contrast to p. dehydrogenase (lipoamide).

- p. dehydrogenase a structurally distinct collection of enzymes containing p. dehydrogenase (lipoamide), dihydrolipoyl transacetylase, and dihydrolipoyl dehydrogenase.

- p. dehydrogenase (cytochrome) an oxidoreductase catalyzing reaction between ferricytochrome b₁ and p. to yield acetate and CO₂, and ferrocytochrome b₁.

- p. dehydrogenase (lipoamide) an oxidoreductase catalyzing conversion of p. and (oxidized) lipoamide to CO₂ and S⁶-acetyldihydrolipoamide in two successive reactions: the first between p. and thiamin pyrophosphate to yield CO₂ and α-hydroxyethylthiamin pyrophosphate (active p.); the second between the last named and lipoamide to regain the thiamin pyrophosphate and yield S⁶-acetylhydrolipoamide. Cf.:α-ketodecarboxylase.

- p. kinase (PK) phosphoenolp. kinase; a phosphotransferase catalyzing transfer of phosphate from phosphoenolp. to ADP, forming ATP and p.; other nucleoside phosphates can participate in the reaction; a key step in glycolysis; a deficiency in p. kinase will lead to hemolytic anemia.

- p. oxidase an oxidoreductase catalyzing the reaction of p., phosphate, and O₂ to yield acetyl phosphate, CO₂, and H₂O₂.

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py·ru·vate pī-'rü-.vāt n a salt or ester of pyruvic acid

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see pyruvic acid

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py·ru·vate (piґroo-vāt) a salt, ester, or anionic form of pyruvic acid. In biochemistry, the term is used interchangeably with pyruvic acid, even though pyruvate technically refers to the negatively charged ion. Pyruvate is the end product of glycolysis, and it in turn may be converted to lactate or acetyl CoA or to ethanol (as in yeasts).