Thermodynamics of simple and mixed complexes of copper(II) with adenosine 5'-monophosphate and spermine.

Thermodynamic parameters pertinent to the equilibria of ternary system copper(II), adenosine 5'-monophosphate (AMP), and 4,9-diazadodecane-1,12-diamine (Spermine, Spe) were determined by means of potentiometric and calorimetric techniques, together with the corresponding parent binary complex parameters. This system could be considered as a model in the study of more complicated biological systems. In particular, it could give useful evidence in the investigation of the interaction between tetramine and DNA. The experimental results seem to suggest that the major contribution in DNA stabilization by means of tetramines is due to the electrostatic interactions occurring between the protonated nitrogen atoms of the amine molecules and the phosphate groups of nucleotides in the nucleic chains.