title: [Distribution of elongation factors EF-1 and EF-2 among components of rabbit reticulocyte lysate].
abstract: The distribution of activity of the elongation factors EF-1 and EF-2 among the components of rabbit reticulocyte lysate separated by sucrose density gradient centrifugation was studied. At low ionic strength (0.01 M KCl) about 30% of the EF-1 activity was found in polyribosomes. At moderate ionic strength (0.1 M KCl) the EF-1 activity was absent in the polyribosomes. An addition of RNA excess to the lysate prior to centrifugation at low ionic strength resulted in elimination of the EF-1 activity from the polyribosomes. This indicates that EF-1 is reversibly bound to the polyribosomes and that EF-1 may be retained on them due to interaction with RNA of polysomes mediated by its RNA-binding site. After dissociation of polyribosomes containing EF-1 in the presence of EDTA and subsequent fractionation of the dissociation products at low ionic strength (0.01 M KCl) the EF-1 activity was revealed in the ribosomal subparticles (predominantly in 60S). At 0.1 M KCl EF-1 mainly sedimented in the zone of distribution of polyribosomal informosomes. The elongation factor EF-2 was not revealed in polyribosomes during lysate centrifugation even at low ionic strength which corresponds to its lower affinity for RNA.
mesh_terms: D000818:Animals; D007700:Kinetics; D009994:Osmolar Concentration; D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000097:blood / Q000302:isolation & purification*; D011132:Polyribosomes / Q000378:metabolism*; D011485:Protein Binding; D012335:RNA, Ribosomal / Q000097:blood*; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*
chemical_list: D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D012335:RNA, Ribosomal
vernacular_title: Raspredelenie faktorov élongatsii EF-1 i EF-2 sredi komponentov lizata retikulotsitov krolika.