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.
Laboratoire de Biophysique, Muséum National d'Histoire Naturelle INSERM U201, CNRS URA 481, Paris, France. mergny@lovelace.infobiogen.fr
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Mergny
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Lacroix
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