Changes in levels of alcohol dehydrogenase during the development of Drosophila melanogaster.
The results of an analysis of the biochemical basis of changes in alcohol dehydrogenase (E.C.1.1.1.1) activity over Drosophila development are presented. The data indicate that (1) the characteristic changes that occur in ADH activity over development are predominantly, it not exclusively, the result of quantitative changes in the amount of enzyme present rather than qualitative changes affecting the enzyme's specific activity and (2) the fluctuations in amount of ADH which occur during development are not the result of the only known form of post-translational modification capable of affecting the biochemical properties of the enzyme. We conclude that developmental changes in amount of ADH are most likely the result of fluctuations in the turnover of the ADH protein.