Noncovalent interactions in ternary complexes of spermine and copper(II) with adenosine 5'-triphosphate and tripolyphosphate.

Thermodynamic characteristics pertinent to the formation equilibria of two ternary systems: 1) Copper(II), 4,9-diazadodecane-1,12-diamine (spermine, Spe), and adenosine 5'-triphosphate (ATP) and 2) Copper(II), Spe, and tripolyphosphate (TPP) have been determined by means of potentiometric and calorimetric techniques, together with the parent binary complex characteristics. Ternary complexes involving ATP can give information useful in the interpretation of bioenergetic reactions and of biological interactions between nucleic acids and polyamines. As a model system, the TPP-containing ternary complexes have been studied, together with the parent binary complexes. The thermodynamic study of these systems is very important because it can give information about the structural environment of the complexes; moreover, it can help in outlining different noncovalent interactions such as coulombic forces and hydrogen bonds.