Biopolymers and cell. 1998; 14 (3): 184 - 190

Self-association of deoxyoligonucleotide d(GpApCpApTpGpTpC) in aqueous solution: H-NMR thermodynamical analysis of the octamer duplex formation

A. N. Veselkov, S. G. Osetrov, V. I. Pahomov, N. V. Veselkova, D. B. Davies

Self-association of deoxyoctanucleotide S'-d(GpApCpApTpGpTpC) in aqueous solution has been studied by one-dimensional and two-dimensional H-NMR spectroscopy (500 and 600 MHz). Two-dimensional homonudear PMR spectroscopy (2D-TOCSY and 2D-NOESY) was used for complete assignments of deoxyoli¬gonucleotide proton signals. Concentration (at temperatures T\ = - 298 K and T2 = 308 K) and temperature dependences of proton chemical shifts of the octamer have been measured. Experimental results have been analysed using the proposed method based on a dimer model of association of the molecules. Equilibrium association constant, malting temperature of the duplex, thermodynamical parameters Atf and AS of the reaction of duplex formation of the octamer in aqueous solution liave been determined. A comparative analysis has been made of the characteristics of the self-association of the deoxyoligonucleotide d(GpApCpApTpGpTpC) with previous data for deoxytetranucleotides of different base sequence.