Immunological confirmation of elevated levels of CuZn superoxide dismutase protein in an artificially selected long-lived strain of Drosophila melanogaster.

Oxidative stress-induced damage is a major causal factor leading to the loss of function characteristic of the aging process. Various antioxidant defenses are marshalled by the organism so as to combat this oxidative damage and delay the onset of senscence. CuZnSOD is one of the major antioxidant enzymes and has been shown to play an important role in the extended longevity of Drosophila melanogaster. Although assays exist with which to measure the CuZnSOD RNA prevalence and enzyme activity, there existed no antibodies that permitted the measurement of the actual amount of Drosophila enzyme protein present. Development of such a tool would enhance our ability to understand mechanisms of antioxidant gene expression in this organism. We have developed a polyclonal antibody against synthetic SOD peptides that is specific for Drosophila CuZnSOD as shown by Western blots. It is very sensitive when tested against native Drosophila CuZnSOD protein. Its use in our experimental system confirms the prior RNA and enzyme activity measurements that indicate that our genetically selected long-lived strain has significantly higher levels of CuZnSOD protein than does the appropriate control strain.