Alcohol Dehydrogenase from Saccharomyces cerevisiae 

1 U corresponds to the amount of enzyme, which oxidizes 1 μmol ethanol per minute at pH 8.8 and 25°C

A 141k Da 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^-3 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)

BioChemika

powder

M_r ~141000

off-white

wet ice

−20°C

3