title: Theoretical NMR study of the pre-melting transition in the d-(CGCGAATTCGCG) and d-(CGCGTATACGCG) self-complementary duplexes.
abstract: The difference between their shielding in a B-DNA duplex and in the single strand having the same conformation has been calculated for all base protons of the dodecamers d-(CGCGAATTCGCG) and d-(CGCGTATACGCG). The calculated chemical shift variations reproduce the qualitative features of the shifts which occur during the pre-melting of the helices. This agreement shows that the pre-melting mechanism consists mainly of a lengthening of the hydrogen bonds between the two strands (in line opening) and that the conformation of the ribophosphate backbone and the orientation of the bases do not undergo major modifications during the first step of the melting.
mesh_terms: D001483:Base Sequence; D004247:DNA; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D013329:Structure-Activity Relationship
chemical_list: D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D004247:DNA