title: 2D-NMR studies of the unnatural duplex alpha-d(TCTAAAC)-beta-d(AGATTTG).
abstract: The unnatural oligonucleotide alpha-d(TCTAAAC) was synthesized and was found more resistant towards endonucleases than its beta-analog. 2D-NMR experiments allowed the assignment of all non-exchangeable aromatic and sugar protons except for the overlapping 5' -5" resonances, as well as the exchangeable imino protons of the parallel hybrid duplex alpha-d (TCTAAAC)-beta-d(AGATTTG). NMR studies show that the strength of the association between the alpha-strand and the beta parallel strand is equivalent to that between their anti-parallel complementary beta-analogs beta-d(CAAATCT) and beta-d(AGATTTG). NOE data provide evidence that both duplexes form stable right-helical duplexes with an anti-conformation on the glycosyl linkages and a Watson-Crick pairing. NOESY and COSY spectra allowed us to determine that alpha and beta deoxyriboses adopt a 3' -exo conformation.
authors: Centre de Biophysique Moléculaire, CNRS, Orléans, France.
authors: G
authors: G
authors: Lancelot
authors: J L
authors: JL
authors: Guesnet
authors: V
authors: V
authors: Roig
authors: N T
authors: NT
authors: Thuong
mesh_terms: D001483:Base Sequence; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis
chemical_list: D009838:Oligodeoxyribonucleotides