Résumé
alpha-Oligodeoxynucleotides containing 5-methylcytosine (mC) and/or 5-bromouracil (BrU) were synthesized. The stability of the corresponding alpha-pyr.beta-pur.beta-pyr triple helice between pH 5.5 and pH 8.0 was studied. Introduction of mC increases tripler stability while introduction of BrU has no effect. Tripler formation was confirmed by mixing curves at pH 6.0. At pH values above 7.0, self-association of the cu strand competes with formation of the alpha-pyr.beta-pur.beta-pyr tripler.