The purification and biochemical properties of alcohol dehydrogenase--"fast (Chateau Douglas)" from Drosophila melanogaster.

Alcohol dehydrogenase has been purified from Drosophila melanogaster lines bearing the AdhF, AdhS, and AdhFCh.D. alleles. Biochemical investigations show that the properties of the purified enzymes are very similar to those of crude enzyme extracts except that the pure enzymes are more heat stable. ADH-FCh.D. resembles ADH-S very closely in specific activity, substrate specificity, and a number of kinetic parameters including limiting values for Km(app.) for ethanol. However, it is considerably more heat stable than either of the two common variants. ADH-F differs from ADH-S and ADH-FCh.D. particularly with regard to the rate of oxidation of secondary alcohols. Atomic absorbtion spectroscopy shows that all three allozymes lack zinc or other divalent cations as active-site components. Peptide mapping experiments identify one very active cysteinyl residue; and amide residues in the NAD+ binding domain.