Dehydrogenases are enzymes that oxidize its substrate by elimination of Wasserstoffanionen (formally H ). They should not be confused with the dehydratases, which split off water. Dehydrogenases belong to the group I ( oxidoreductases ) of the EC classification, they occupy the two subclasses EC 1.1.1 -. , And EC 1.1.2. -. The electrons and the split-off hydrogen are transferred to cofactors such as NAD or FAD.
Depending on the substrate various dehydrogenases can be distinguished. For example, the enzyme that converts in the liver during alcohol metabolism of ethanol to acetaldehyde ( ethanal ), alcohol dehydrogenase ( EC 22.214.171.124 ). The oxidation of L- lactate to pyruvate catalyzed by lactate dehydrogenase ( EC 126.96.36.199. ).
Like all enzymes catalyze reversible reactions dehydrogenases in the counter- reaction, here the reduction. Thus, the counter-reaction to the above oxidation of lactate to pyruvate is at least as important as this yourself will take place in glycolysis when pyruvate can not be introduced via acetyl -CoA in the citric acid cycle and NAD is required for other reactions here especially for the glyceraldehyde -3-phosphate dehydrogenase ( GAPDH). The enzyme involved in the reduction of pyruvate to lactate is again the lactate dehydrogenase.
- Protein group