Triple helix-forming oligonucleotides which make imperfect Watson-Crick duplexes that compete with the creation of the triplex.
Because of the repetitive nature of the sequence, when titrating a G,A-rich, triple helix-forming oligonucleotide (TFO) with increasing concentrations of target duplex in order to obtain the dissociation constant of the complex, a duplex is sometimes first generated at intermediate concentrations of the target. This duplex is based on an imperfect Watson-Crick pairing of the TFO to the pyrimidine-rich strand of the target. An explanation is proposed for this duplex being obtained only in a certain domain of the titration range, before the triple helix becomes predominant.
Porumb
H
H
Laboratoire de Spectroscopie Bio-moléculaire, Université Paris-Nord, Bobigny, France. porumb@infobiogen.fr
Gousset
H
H
Taillandier
E
E
D020029:Base Pairing; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D008274:Magnesium / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*
D009841:Oligonucleotides; C051802:triplex DNA; D004247:DNA; D008274:Magnesium