Immunological studies of lipogenic enzymes during aging

The effects of aging on enzyme qualities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase were investigated. The Ouchterlony double-diffusion pattern showed that the enzymes from livers of rats of different ages are immunologically similar to each other. In addition, immunochemical titration demonstrated that the changes in the levels of activity of rats of different age are accompanied by proportionate changes in the quantity of the enzyme protein. The Kms of the enzymes for substrates were not altered by aging. It is suggested that the age-dependent impairments of the enzyme induction (Iritani, N., Fukuda, H., and Fukuda, E. (1981) Biochim. Biophys. Acta, 665, 639) can be ascribed to decreases in the rise of enzyme protein quantities.