[Use of spin labels for studying the association of adenosine, adenosine-5'-mono-, di- and triphosphate in aqueous...

Possibility of spin label studies as a method of investigation of different molecular associations is considered with adenosine, adenosine-5'-mono, di- and triphosphate as examples. The proposed method is based on dependence of the parameters of spin-labelled derivatives ESR-spectra on concentration of corresponding unlabelled compounds. Being highly sensitive the method takes the advantage of obtaining not only thermodynamic characteristics of association but dynamic parameters of molecular mobility of the associates as well. It is shown by this method that base-phosphate interaction participates in nucleotide association, together with the stacking interaction.