H-1-NMR INVESTIGATION OF DEOXYTETRANUCLEO SIDE TRIPHOSPHATES D(TPGPCPA) SELF-ASSOCIATION ON AQUEOUS-SOLUTION

Self-association of deoxytetraribonucleoside triphosphate 5'-d(TpGpCpA ) molecules in aqueous solution has been studied by one-dimensional an d two-dimensional H-1-NMR spectroscopy (500 MHz). Two-dimensional homo nuclear PMR spectroscopy (2D-COSY and 2D-NOESY) was used for complete assignments of tetranucleotide proton signals. Concentration and tempe rature dependences of d(TpGpCpA) chemical shifts have been measured. E xperimental results have been analyzed using dimer model of molecules association. Equilibrium association constant, values of limiting chem ical shifts of tetranucleotide protons in the associate and thermodyna mical parameters Delta H and Delta S of the association reaction have been determined. Comparative analysis of self-association characterist ics for d(TpGpCpA) and its isomeric deoxytetranucleotide d(ApGpCpT) ha s been made.