Biochem/physiol Actions

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: 5.4-5.8Optimal 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 MK_M (methanol = 1.3 × 10^-1 MK_M (isopropanol) = 1.4 × 10^-1 MInhibitors: 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)

General description

We are committed to bringing you Greener Alternative Products, which adhere to one or more of The 12 Principles of Greener Chemistry. This product has been enhanced for energy efficiency and waste prevention when used in fuel cell research. For more information see the article in biofiles.

Packaging

7500, 15000, 30000, 75000, 150000 units in poly bottle

Physical form

Solids containing ﹤2% citrate buffer salts

Specifications

The dried enzyme has been stored for several weeks in a vacuum desiccator with little loss in activity. According to experiments described by A. Kornberg,3 the enzyme can be stored in the frozen state and can be thawed repeatedly without marked loss of activity.

Unit Definition

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