title: Preparation of spin-labeled poly(U) and its activity in assays with eukaryotic ribosomes.
abstract: ESR studies on the interaction of spin-labeled polynucleotides with ribosomes require a sufficient label-to-nucleotide ratio. Using three different spin labels (SL) we have elaborated a technique to label poly(U) up to a ratio of 1 SL per 30 uridine residues. This ratio is much higher than maximal values obtained by other authors. The SL-poly(U) was shown to have the same activity as unlabeled poly(U) to direct synthesis of poly(Phe). SL-poly(U) binds to rat liver ribosomes in the presence of Mg2+ as shown by ESR. Titration with EDTA leads to a release of SL-poly(U) from ribosomes.
mesh_terms: D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D005057:Eukaryotic Cells / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D011072:Poly U; D051381:Rats; D012270:Ribosomes / Q000378:metabolism; D013113:Spin Labels
chemical_list: D013113:Spin Labels; D011072:Poly U