alpha-DNA X: alpha and beta tetrathymidilates covalently linked to oxazolopyridocarbazolium (OPC): comparative stabilization of oligo beta-[dT]:oligo beta-[dA] and oligo alpha-[dT]:oligo beta-[dA] duplexes by the intercalating agent.
The influence of the intercalating oxazolopyridocarbazolium (HOPC) on the stabilization of modified oligonucleotides: alpha-T4c5OPC or beta-T4c5OPC associated to beta-oligo (dA) was studied. It appears that the situation is different from what has been observed for the interaction of these modified oligonucleotides with poly (rA). The higher free energy of formation of the alpha-T4c5OPC :beta-oligo(dA), when compared to beta-T4c5OPC, is essentially due to the overall stability added to this system by the intercalator. This enhanced stability comes from a higher number of binding sites of HOPC for the alpha:beta duplex together with a lower van't Hoff energy of formation of the alpha:beta duplex.
Bazile
D
D
Unité de Biochemie, URA 158 CNRS and U 140 INSERM, Institut Gustave-Roussy, Villejuif, France.
Gautier
C
C
Rayner
B
B
Imbach
J L
JL
Paoletti
C
C
Paoletti
J
J
D002227:Carbazoles; D004247:DNA / Q000138:chemical synthesis*; D004355:Drug Stability; D007202:Indicators and Reagents; D007364:Intercalating Agents; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis*; D013056:Spectrophotometry, Ultraviolet
D002227:Carbazoles; D007202:Indicators and Reagents; D007364:Intercalating Agents; D009838:Oligodeoxyribonucleotides; C027903:oligo (dT); C061416:oxazolopyridocarbazole; C061415:oligo(dT)-oligo(dA); D004247:DNA