title: Hydrogen-bonded complexes of the ribodinucleoside monophosphates in aqueous solution. Proton magnetic resonance studies.
abstract: A proton magnetic resonance study of the chemical shifts of a series of ribodinucleoside monophosphates in neutral H2O solution has been recorded in the 1-100 mM concentration range. The self-complementary dinucleoside monophosphates CpG and GpC and the complementary mixture GpU + ApC form intermolecular hydrogen-bonded complexes at low temperatures. The amino proton chemical shifts in the CpG and GpC spectra are consistent with the formation of a miniature double helical dimer in neutral aqueous solution at low temperatures (approximately 2 degrees C). The complementary mixture of dinucleosides GpU + ApC formed much less stable complexes than either GpC or CpG, while UpA did not show any indication of the formation of intermolecular hydrogen-bonded complexes. This result is consistent with the well-known observation that the stability of a double helix is proportional to the percent of G-C base pairs present.
mesh_terms: D001665:Binding Sites; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides; D013696:Temperature; D013816:Thermodynamics
chemical_list: D009843:Oligoribonucleotides