Study by (23)Na-NMR, (1)H-NMR, and ultraviolet spectroscopy of the thermal stability of an 11-basepair oligonucleotide.
23Na-NMR, (1)H-NMR, and ultraviolet (UV) spectroscopy have been used to study the thermal stability of the double helix structure of an 11-basepair oligonucleotide. The denaturation curves obtained by (23)Na-NMR and UV are analyzed using a two-state model. The melting temperature and DeltaH(0) obtained are identical within experimental error, suggesting that modifications in the ionic atmosphere, probed by (23)Na-NMR, and the modifications in the basepair stacking, probed by UV, occur at the same temperature. Additional dynamical information on the denaturation process has been obtained by (1)H-NMR: slow exchange is observed between the thymine methyl resonances, and the disappearance of imino protons shows that a single basepair opening does not contribute significantly to proton exchange.
Cahen
P
P
Laboratoire de Chimie Organique E.P. (CP165/64), Université Libre de Bruxelles, 1050 Bruxelles, Belgium.
Luhmer
M
M
Fontaine
C
C
Morat
C
C
Reisse
J
J
Bartik
K
K
D020029:Base Pairing; D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry*; D011522:Protons; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D009841:Oligonucleotides; D011522:Protons; D004247:DNA