The structure and amount of actin in IMR-90 fibroblasts.
Double-labelling and peptide isolation have been used to examine the homology between the actin of IMR-90 human embryo fibroblasts and muscle actin. After separation of mixtures of [14C]carboxymethylated muscle actin and [3H]carboxymethylated proteins of IMR-90 cells of electrophoresis on sodium dodecyl sulphate-containing polyacrylamide gels, peptides were generated from the material co-migrating with actin by digestion with chymotrypsin. Peptides homologous with peptides accounting for Cys-217, Cys-256, Cys-284 and Cys-373 of muscle actin are present in this material, but no peptide homologous with a Cys-10-containing peptide was detected. From the amount of actin-derived peptides present, the actin content of IMR-90 fibroblasts was calculated to be 4.2% of the total protein of these cells.
D000199:Actins / Q000032:analysis*; D002460:Cell Line; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000032:analysis*; D006801:Humans; D009132:Muscles / Q000032:analysis; D010455:Peptides / Q000032:analysis
D000199:Actins; D010455:Peptides