Resolution of parallel and antiparallel oligonucleotide triple helices formation and melting processes by multivariate curve resolution.
A procedure is described for the complete resolution of concentration profiles of oligonucleotide triplexes as a function of pH and temperature. The pH and temperature ranges at which triplexes are present and the relative concentrations of all the species involved in acid-base and conformational equilibria are successfully estimated from Multivariate Curve Resolution analysis of UV absorbance spectra recorded along acid-base titrations and melting experiments of single stranded, hairpin and their mixtures. The dependence of formation constants upon pH was successfully estimated. The hairpin h26 (5'-GAAGGAGGAGA-TTTT-TCTCCTCCTTC-3'), and the single stranded oligonucleotides s11CT (5'-CTTCCTCCTCT-3'), s11AG (5'-AGAGGAGGAAG-3') and s11TG (5'-TGTGGTGGTTG-3') were synthesized and their protonation and conformational equilibria were studied in detail. The procedure was shown to be especially useful for the study of triplexes with a low hypochromism upon formation.
Jaumot
J
J
Departament de Quimica Analitica, Universitat de Barcelona, Marti Franques 1 -11, 08028 Barcelona, Spain.
Aviña
A
A
Eritja
R
R
Tauler
R
R
Gargallo
R
R
D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015999:Multivariate Analysis; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry*; D013696:Temperature
D009841:Oligonucleotides; C051802:triplex DNA; D004247:DNA