[Self-association of deoxytetraribonucleoside triphosphates d(TpGpCpA) in an aqueous solution by 1H NMR spectroscopy].

Self-association of deoxytetraribonucleoside triphosphate 5'-d(TpGpCpA) molecules in aqueous solution has been studied by one-dimensional and two-dimensional 1H-NMR spectroscopy (500 MHz). Two-dimensional homonuclear PMR spectroscopy (2D-COSY and 2D-NOESY) was used for complete assignments of tetranucleotide proton signals. Concentration and temperature dependences of d(TpGpCpA) proton chemical shifts have been measured. Experimental results have been analyzed using dimer model of molecules association. Equilibrium association constant, values of limiting chemical shifts of tetranucleotide protons in the associate and thermodynamic parameters delta H and delta S of the association reaction have been determined. Comparative analysis of self-association characteristics for d(TpGpCpA) and its isomeric deoxytetranucleotide d(ApGpCpT) has been made.