title: Fidelity of histone synthesis in cultured human fibroblasts.
abstract: The results in the literature to support Orgel's general error hypothesis of ageing only provide indirect evidence that errors in protein synthesis increase during senescence. This study attempts to provide direct evidence of errors in protein synthesis by measuring the misincorporation of 35S-methionine into histone H1 obtained from young and old fibroblasts (MRC-5). The conclusions that can be drawn from this study are: (a) the error level for the misincorporation of methionine into histone H1 is less than 7 methionines/10(5) amino acids and 2-3 methionines/10(4) amino acids in young and old cells respectively; (b) a methionine containing fraction associated with H1 is obtained after the final purification. The amount of this fraction increases with the age of the cell culture as does the number of methionine residues; (c) there is a variation in the complexity of H1 polypeptide chains, the complexity increasing with the age of cultured cells.
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism*; D006657:Histones / Q000096:biosynthesis*; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D013997:Time Factors
chemical_list: D006657:Histones; D008715:Methionine; D008239:Lysine