A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyze reverse as well as forward reactions, and in some cases this has physiological significance: for example, alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde in animals, but in yeast it catalyzes the production of ethanol from acetaldehyde.
Alcohol dehydrogenases (ADH) (EC 1.1.1.1) are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to NADH. In humans and many other animals, they serve to break down alcohols that are otherwise toxic, and they also participate in the generation of useful aldehyde, ketone, or alcohol groups during the biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD+.
Acetaldehyde dehydrogenases are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetyl-CoA. This can be summarized as follows:
Aldehyde dehydrogenases are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes to carboxylic acids. The oxygen comes from a water molecule. To date, nineteen ALDH genes have been identified within the human genome. These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes.
Aldehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH2 gene located on chromosome 12. This protein belongs to the aldehyde dehydrogenase family of enzymes. Aldehyde dehydrogenase is the second enzyme of the major oxidative pathway of alcohol metabolism. Two major liver isoforms of aldehyde dehydrogenase, cytosolic and mitochondrial, can be distinguished by their electrophoretic mobilities, kinetic properties, and subcellular localizations.
Glycerol dehydrogenase (EC 1.1.1.6, also known as NAD+-linked glycerol dehydrogenase, glycerol: NAD+ 2-oxidoreductase, GDH, GlDH, GlyDH) is an enzyme in the oxidoreductase family that utilizes the NAD+ to catalyze the oxidation of glycerol to form glycerone (dihydroxyacetone).
In enzymology, histidinol dehydrogenase (HIS4) (HDH) (EC 1.1.1.23) is an enzyme that catalyzes the chemical reaction
In enzymology, a methanol dehydrogenase (MDH) is an enzyme that catalyzes the chemical reaction:
In enzymology, an alcohol dehydrogenase (acceptor) (EC 1.1.99.8) is an enzyme that catalyzes the chemical reaction
In enzymology, an alcohol oxidase (EC 1.1.3.13) is an enzyme that catalyzes the chemical reaction
Long-chain alcohol oxidase is one of two enzyme classes that oxidize long-chain or fatty alcohols to aldehydes. It has been found in certain Candida yeast, where it participates in omega oxidation of fatty acids to produce acyl-CoA for energy or industrial use, as well as in other fungi, plants, and bacteria.
In enzymology, a betaine-aldehyde dehydrogenase (EC 1.2.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a mycothiol-dependent formaldehyde dehydrogenase (EC 1.1.1.306) is an enzyme that catalyzes the chemical reaction
Alcohol dehydrogenase 1B is an enzyme that in humans is encoded by the ADH1B gene.
Alcohol dehydrogenase 1C is an enzyme that in humans is encoded by the ADH1C gene.
The short-chain dehydrogenases/reductases family (SDR) is a very large family of enzymes, most of which are known to be NAD- or NADP-dependent oxidoreductases. As the first member of this family to be characterised was Drosophila alcohol dehydrogenase, this family used to be called 'insect-type', or 'short-chain' alcohol dehydrogenases. Most members of this family are proteins of about 250 to 300 amino acid residues. Most dehydrogenases possess at least 2 domains, the first binding the coenzyme, often NAD, and the second binding the substrate. This latter domain determines the substrate specificity and contains amino acids involved in catalysis. Little sequence similarity has been found in the coenzyme binding domain although there is a large degree of structural similarity, and it has therefore been suggested that the structure of dehydrogenases has arisen through gene fusion of a common ancestral coenzyme nucleotide sequence with various substrate specific domains.
Methanol dehydrogenase (cytochrome c) (EC 1.1.2.7, methanol dehydrogenase, MDH) is an enzyme with systematic name methanol:cytochrome c oxidoreductase. This enzyme catalyses the following chemical reaction
Quinate dehydrogenase (quinone) (EC 1.1.5.8, NAD(P)+-independent quinate dehydrogenase, quinate:pyrroloquinoline-quinone 5-oxidoreductase) is an enzyme with systematic name quinate:quinol 3-oxidoreductase. This enzyme catalyses the following chemical reaction
Alcohol dehydrogenase (azurin) (EC 1.1.9.1, type II quinoprotein alcohol dehydrogenase, quinohaemoprotein ethanol dehydrogenase, QHEDH, ADHIIB) is an enzyme with systematic name alcohol:azurin oxidoreductase. This enzyme catalyses the following chemical reaction
Methanol dehydrogenase (nicotinoprotein) (EC 1.1.99.37, NDMA-dependent methanol dehydrogenase, nicotinoprotein methanol dehydrogenase, methanol:N,N-dimethyl-4-nitrosoaniline oxidoreductase) is an enzyme with systematic name methanol:acceptor oxidoreductase. This enzyme catalyses the following chemical reaction
