Thermal difference spectra: a specific signature for nucleic acid structures.
We show that nucleic acid structures may be conveniently and inexpensively characterized by their UV thermal difference spectra. A thermal difference spectrum (TDS) is obtained for a nucleic acid by simply recording the ultraviolet absorbance spectra of the unfolded and folded states at temperatures above and below its melting temperature (T(m)). The difference between these two spectra is the TDS. The TDS has a specific shape that is unique for each type of nucleic acid structure, a conclusion that is based on a comparison of >900 spectra from 200 different sequences. The shape of the TDS reflects the subtleties of base stacking interactions that occur uniquely within each type of nucleic acid structure. TDS provides a simple, inexpensive and rapid method to obtain structural insight into nucleic acid structures, which is applicable to both DNA and RNA from short oligomers to polynucleotides. TDS complements circular dichroism as a tool for the structural characterization of nucleic acids in solution.
Mergny
Jean-Louis
JL
Laboratoire de Biophysique, Muséum National d'Histoire Naturelle, USM503, INSERM U 565, CNRS UMR 5153, 43 rue Cuvier, 75231 Paris cedex 05, France. faucon@mnhn.fr
Li
Jing
J
Lacroix
Laurent
L
Amrane
Samir
S
Chaires
Jonathan B
JB
D004247:DNA / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012313:RNA / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D012313:RNA; D004247:DNA