Following G-quartet formation by UV-spectroscopy.
Oligodeoxynucleotides which include stretches of guanines form a well-known tetrameric structure. We show that the recording of reversible absorbance changes at 295 nm allows to precisely monitor intramolecular guanine (G)-quartet formation and dissociation. Accurate Tm and thermodynamic values could be easily extracted from the data, whereas classical recordings at 260 nm led to a much larger uncertainty and in extreme cases, to completely inaccurate measurements. This inverted denaturation profile was observed for all G-quartet-forming oligonucleotides studied so far. This technique is very useful in all cases where intramolecular or intermolecular quadruplex formation is suspected.
Mergny
J L
JL
Laboratoire de Biophysique, Muséum National d'Histoire Naturelle INSERM U201, CNRS URA 481, Paris, France. mergny@lovelace.infobiogen.fr
Phan
A T
AT
Lacroix
L
L
D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry*; D015497:HIV-1; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D012367:RNA, Viral / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D012367:RNA, Viral; D006147:Guanine; D004247:DNA