Analysis of the proteins of aging Caenorhabditis elegans by high resolution two-dimensional gel electrophoresis.

The metabolic rate decreases dramatically as a function of age in the nematode worm Caenorhabditis elegans. Superoxide anion production, which is tightly linked to oxygen consumption, and thus to metabolic rate, drops to a 20-fold lower level in 10-day-old, senescent worms, as compared to 4-day-old young adults. In a long-lived mutant strain of the same species metabolic activity is much better preserved. High resolution two-dimensional gel electrophoresis was employed to study alterations in the protein profile, correlating with changes of metabolic activity. Surprisingly, few proteins show age- or age- and strain-specific variations of spot intensity. The abundance of the huge majority of proteins displayed on these gels remains unaltered, irrespective of age and strain differences. These results imply that there are no major age-related alterations of proteins due to faulty protein synthesis or free radical attack, and that age-related changes in the rate of protein synthesis and breakdown must be strictly coordinated throughout the aging process.