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D Gershon

Publications and source records attributed to D Gershon.

204 records · Page 12Linked to original sources
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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.

Aging↗
PubMedDate not supplied

The effect of short- and long-term exercise on aldolase activity in muscles of CW-1 and C57/BL mice of various ages.

The effect of wheel running on the levels of fructose 1,6-bisphosphate aldolase A (EC 4.1.2.13) in striated muscles of young and old mice was compared. Short-term (6-10 weeks) and long-term (over 12 months) regimens were included in the study. The studies were conducted on the CW-1 outbred strain and on the C57/BL inbred strain of mice. It was shown that, in the short-term regimens, old animals of both strains showed either no increase (C57/BL) or a reduction (CW-1) in aldolase activity in hind leg muscles. On the other hand, young animals of both strains showed increases in aldolase activity of 10-20%. In the long-term regimen young and intermediate age animals showed 30-100% increases in aldolase activity in hind leg muscles over control sedentary animals. This adaptive capacity to exercise was not observed in old animals. However, long-term exercise regimen prevented the age-associated decline in aldolase activity found in sedentary animals.

Aging↗
PubMedDate not supplied

Alterations in the chaperone activity of HSP70 in aging organisms.

The reduced capacity to respond to stress is one of the major characteristics of senescent organisms. This decline is a major cause of morbidity and eventually has lethal consequences. Heat-shock proteins (HSPs) constitute a major defense system which allows recovery from adverse modes of stress such as elevated temperatures, alcohol, toxic heavy metals (e.g., cadmium), some forms of oxidative and post-ischemic stress and other forms of environmental insults. It is, therefore, important to investigate the functional capacity of HSPs as a function of organismal age at the molecular level. We chose to test the major stress-inducible form, HSP70. This protein was purified to homogeneity from livers of young (6 months) and old (27 months) rats. Its functional capacity was examined by the ability to protect the activity of creatine kinase (CPK) and aldolase A (Ald A) treated at 56 degrees C and 51 degrees C, respectively. We first established that when HSP70 is present during the heat treatment it protected CPK by 80-90% and Ald A by 50-60%. This protection was specific and was essentially dependent upon ATP and Mg(2+). Most important, HSP70 from old rats gave only 50% protection of CPK as compared to the protein of young animals. The significance of the results in terms of cellular physiology in aging is discussed.

Journal Article↗