Purification and partial characterization of alcohol dehydrogenase from wheat

Further support for hypotheses proposed earlier for the genetic control and subunit composition of the alcohol dehydrogenase of Triticum has been obtained through the purification and partial characterization of the enzyme. The alcohol dehydrogenase of the wheat T. monococcum was purified 103-fold to a specific activity of 55,900 units/mg. Purification was achieved using streptomycin sulfate precipitation, gel filtration chromatography, DEAE-cellulose anion-exchange chromatography, and preparative isoelectric focusing. The native enzyme has a molecular weight of 116,000 and a dimeric subunit structure. The apparent Michaelis constants are 1.2 × 10 −2 m for ethanol and 1 × 10 −4 m for NAD. The substrate specificity of wheat alcohol dehydrogenase differs significantly from the substrate specificities of the enzymes of horse and yeast.