Characterization of two high molecular weight proteins immunoprecipitated with an antibody against rat liver cytochrome c oxidase.
Isolated rat hepatocytes were labelled with [35S]methionine, dissolved in Triton X-100-containing buffer, and incubated with antibodies against rat liver cytochrome c oxidase. After separation by dodecyl sulfate-gel electrophoresis the fluorogram of immunoprecipitated proteins showed two labelled bands with apparent molecular weights of 52000 and 182000. The immunological relationship of the two proteins to cytochrome c oxidase was demonstrated by immunocompetition with the isolated enzyme and with purified subunits IV-VIII. Although the precursor nature of the two described proteins for cytoplasmically synthesized subunits of cytochrome c oxidase cannot be excluded, the following observations do not support this assumption: 1) The amount of incorporated radioactivity is too high; 2) they are exclusively located with the microsomal fraction; 3) the turnover is rather slow, compared to that of known precursor proteins.
D000818:Animals; D000936:Antigen-Antibody Complex; D000941:Antigens / Q000032:analysis*; D003576:Electron Transport Complex IV / Q000276:immunology* / Q000378:metabolism; D007106:Immune Sera; D007118:Immunoassay; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D051381:Rats
D000936:Antigen-Antibody Complex; D000941:Antigens; D007106:Immune Sera; D046911:Macromolecular Substances; D003576:Electron Transport Complex IV