Decreased protein and puromycinyl-peptide degradation in livers of senescent mice.
Liver protein-degradation rates were determined in young and old C57B1 mice by the method of Swick & Ip [(1974) J. Biol. Chem. 249, 6836-6841]. The results indicated a marked age-related increase in the half-lives of short-lived proteins in the nuclear, mitochondrial, lysosomal and 100000 g-supernatant cellular fractions and in total trichloroacetic acid-precipitable proteins. The efficiency of the degradation system in removing aberrant proteins from livers of young and old mice was tested. The time required for 50% disappearance of puromycinyl-peptides changed from about 20 min in 6-month-old mice to approx. 150 min in 24-month-old animals. These findings suggest that in old animals the proteolytic activity involved in degradation of aberrant proteins, and presumably of "native proteins, is markedly defective.
D000375:Aging; D000818:Animals; D005260:Female; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011506:Proteins / Q000378:metabolism*; D011691:Puromycin / Q000031:analogs & derivatives* / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D014238:Trichloroacetic Acid
D011506:Proteins; C031736:peptidyl-puromycin; D011691:Puromycin; D014238:Trichloroacetic Acid