In enzymology, a pyruvate dehydrogenase (cytochrome) (EC 1.2.2.2) is an enzyme that catalyzes the chemical reaction

pyruvate + ferricytochrome b₁ + H₂O ${\displaystyle \rightleftharpoons }$ acetate + CO₂ + ferrocytochrome b₁

The 3 substrates of this enzyme are pyruvate, ferricytochrome b1, and H₂O, whereas its 3 products are acetate, CO₂, and ferrocytochrome b1.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is pyruvate:ferricytochrome-b1 oxidoreductase. Other names in common use include pyruvate dehydrogenase, pyruvic dehydrogenase, pyruvic (cytochrome b1) dehydrogenase, pyruvate:ubiquinone-8-oxidoreductase, and pyruvate oxidase (ambiguous). This enzyme participates in pyruvate metabolism. It has 2 cofactors: FAD, and Thiamin diphosphate.

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