title: The effect of (2'-5') and (3'-5') phosphodiester linkages on conformational and stacking properties of cytidylyl-cytidine in aqueous solution.
abstract: Conformational properties of (2'-5') and (3'-5') CpC have been determined by proton magnetic resonance spectroscopy at 220 MHz. The ribose ring structures are predominantly 3E with the exception of the ring from the 2'-phosphate fragment of C(2'-5')pC which exhibits an 2E pucker. Bases are oriented anti with respect to the ribose and the conformations about C4'-C5', C5'-O5', C3'-O3' (C2'-O2') are gg, g'g', and g+ in equilibrium g-, respectively. The dimers exist as mixtures of stacked (g+g+ and g-g- about the P-O(C) bonds) and unstacked species at 20 degrees C. Stacking is estimated to be 35% in both dimers.
mesh_terms: D003596:Cytosine; D003597:Cytosine Nucleotides; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009841:Oligonucleotides; D009843:Oligoribonucleotides; D010710:Phosphates; D012266:Ribose; D013329:Structure-Activity Relationship
chemical_list: D003597:Cytosine Nucleotides; D009841:Oligonucleotides; D009843:Oligoribonucleotides; D010710:Phosphates; D012266:Ribose; D003596:Cytosine