title: Conformational characteristics of the trinucleoside diphosphate xyloA2'-5'xyloA2'-5'xyloA. A nuclear magnetic resonance and CD study.
abstract: In this paper the conformational analysis of the 2'-5' linked xylotrinucleotide xA2'-5'xA2'-5'xA is reported. The title compound is an analogue of A2'-5'A2'-5'A, which compound was shown to display inhibitive effects on protein synthesis. The complete 1H-NMR assignment of the high field spectral region of the xylose trimer is given. Modes of base-base stacking are extracted from coupling constant data at various temperatures. Circular dichroic (CD) spectra confirm the presence of stacked states at low temperature. Xylonucleosides are known to prefer the N-type sugar conformation. However, in the present trimer the S-type conformer is suggested to partake in stacked conformations. Two types of stacking in the two constituent dimer fragments of the trimer are proposed to rationalize the NMR data: xA(1)N-xA(2)S and xA(2)N-xA(3)S.
mesh_terms: D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides; D013329:Structure-Activity Relationship; D014994:Xylose
chemical_list: D009841:Oligonucleotides; D014994:Xylose