Alcohol Dehydrogenase from Saccharomyces cerevisiae

Research area: Neuroscience

Yeast alcohol dehydrogenase 1 (ADH1) belongs to the family of zinc-containing alcohol dehydrogenases. It is a homotetramer with each subunit containing one catalytic domain and coenzyme-binding domain.

Alcohol dehydrogenase has been used along with lactic dehydrogenase for the enzymatic reduction of acetaldehyde using sodium(R,S)-[2-³H] lactate. It has also been used to study the inhibitory effect of zinc-chelated silymarin flavonolignans on yeast alcohol dehydrogenase.

Ethanol concentration can be determined colorimentrically by monitoring the enzymatic reduction of NAD using alcohol dehydrogenase after preremoval of the aldehyde group.

Yeast alcohol dehydrogenase 1 (YADH1) catalyzes the conversion of acetaldehyde to ethanol during glucose fermentation pathway. It is also implicated in the production of alcohol from amino acid breakdown via the Ehrlich pathway.

ADH (alcohol dehydrogenase) is one of the first enzymes to be isolated and purified. NAD⁺ is its coenzyme. Three isozymes of yeast ADH, that is, yeast alcohol dehydrogenase-1, 2 and 3 (YADH-1, -2, -3) have been identified. YADH-1 is expressed during anaerobic fermentation, YADH-2 is expressed in the cytoplasm and YADH-3 is localized to the mitochondria. A 141kDa tetramer containing 4 equal subunits. The active site of each subunit contains a zinc atom. Each active site also contains 2 reactive sulfhydryl groups and a histidine residue.

Isoelectric point: 5.4-5.8

Optimal pH: 8.6-9.0

Substrates: Yeast ADH is most active with ethanol and its activity decreases as the size of the alcohol increases or decreases. Branched chain alcohols and secondary alcohols also have very low activity.

K_M (ethanol) = 2.1 × 10^-2 M
K_M (methanol = 1.3 × 10^-1 M
K_M (isopropanol) = 1.4 × 10^-1 M

Inhibitors: Compounds that react with free sulfhydryls, including N-alkylmaleimides and iodoacetamide.
Zinc chelator inhibitors, including 1,10-phenanthroline,
8-hydroxyquinoline, 2,2′-dipyridyl, and thiourea.
Substrate analogue inhibitors, including β-NAD analogs, purine and pyrimidine derivatives, chloroethanol, and fluoroethanol.

Extinction Coefficient: E^1% = 14.6 (water, 280 nm)

Solids containing ≤ 2% citrate buffer salts

Dissolves in water at a concentration of 1 mg/mL to form a clear to slightly hazy, colorless to faintly yellow colored solution.

One unit will convert 1.0 μmole of ethanol to acetaldehyde per min at pH 8.8 at 25 °C.

Contains bound β-NAD and β-NADH and is not suitable for the recycling microassay of β-NAD and β-NADH. If you require ADH for this purpose, see Catalog No. A3263.