title: [The structural characteristics of the polyribosomes in the rat liver studied by means of a tritium label].
abstract: Polyribosomes isolated from the rat liver in a medium with low ionic strength were irradiated by "hot" tritium atoms under conditions providing for the replacement of the hydrogen atoms located at the surface of polyribosomes by tritium. After fractionation of such polyribosomes, the radioactivity of the obtained fractions was measured and their proportions were calculated for the total surface accessible for the tritium atoms (in %), as well as their specific radioactivity. The material loosely associated with the polyribosomes and containing amino acyl-tRNA-synthetases is more radioactive than rRNA and r-proteins, especially concerning their specific radioactivity. This suggests that the material is organized as individual molecules located on the surface of ribosomes. The specific radioactivity of the RNA-component of this material (tRNA) is twice that of proteins, thus suggesting its surface localization in the composition of loosely associated material. Based on the pattern of labeling of rRNA and r-proteins of the native and preliminarily dissociated polyribosomes, we propose that the material, loosely associated with the polyribosomes, has affinity to both rRNA and r-proteins.
authors.forename: Iu I
authors.initials: IuI
authors.lastname: Mitrokhin
authors.forename: S T
authors.initials: ST
authors.lastname: Sizova
authors.forename: Iu M
authors.initials: IuM
authors.lastname: Rumiantsev
authors.forename: A V
authors.initials: AV
authors.lastname: Shishkov
authors.forename: I Z
authors.initials: IZ
authors.lastname: Mitsova
authors.forename: I N
authors.initials: IN
authors.lastname: Todorov
mesh_terms: D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D007553:Isotope Labeling / Q000379:methods; D008099:Liver / Q000000981:diagnostic imaging / Q000648:ultrastructure*; D011132:Polyribosomes / Q000000981:diagnostic imaging / Q000648:ultrastructure*; D012313:RNA / Q000648:ultrastructure; D011877:Radionuclide Imaging; D051381:Rats; D014316:Tritium
chemical_list: D014316:Tritium; D012313:RNA