Age related alterations in purified fructose-1,6-diphosphate aldolase from the nematode Turbatrix aceti

Fructose-1,6-diphosphate aldolase has been purified to homogeneity 62.0 and 58.3 fold from young and old nematodes respectively. The aldolase preparations from young (7 days) and old (35 days) animals are indistinguishable in their electrophoretic mobility, molecular weight of the tetramer (158,000) and monomer (40,000), and Km, although the "old" enzyme is more heat stable than the "young" enzyme. Enzyme from old animals has only about 55% specific activity per mg purified protein of the "young" enzyme and its catalytic activity per unit of enzyme antigen is about 50% of that of the enzyme from young animals. Immunological identity of purified enzyme from old and young animals was established by the Ouchterlony technique by antiserum produced against purified "young" enzyme and antiserum against purified "old" enzyme. Thus, this work shows for the first time that the altered form of an enzyme which appears in senescent animals apparently does not possess extra antigenic sites which are acquired as a function of age.