title: Osmium-labeled polynucleotides: reaction of osmium tetraoxide, with poly-1,N6-ethenoadenylic acid.
abstract: Osmium tetraoxide, in the presence of ligands such as pyridine and bipyridine, adds across the etheno bridge of 1,N6-etheno-9-methyladenine and poly-1,N6-ethenoadenylic acid. The Os:P ratio in the labeled polynucleotide was approximately equal to 1 when bipyridine was used as the stabilizing ligand. A similar study with polycytidylic acid, which had been partially modified with chloroacetaldehyde so that some bases were converted to 3,N4-ethenocytosine, gave an OS:P ratio of approximately equal to 1.3. Calf-thymus DNA, in which the adenine and cytosine bases were modified by chloroacetaldehyde, gave an Os:P ratio of approximately equal to 1 after 24 h. These results suggest that 3,N4-ethenocytosine will add two Os labels.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA; D004985:Ethenoadenosine Triphosphate / Q000031:analogs & derivatives*; D008024:Ligands; D009992:Osmium; D009993:Osmium Tetroxide; D011061:Poly A; D011066:Poly C; D011725:Pyridines
chemical_list: D004985:Ethenoadenosine Triphosphate; D008024:Ligands; D011725:Pyridines; D011061:Poly A; D009992:Osmium; D011066:Poly C; D000255:Adenosine Triphosphate; D004247:DNA; D009993:Osmium Tetroxide