³¹P-und ¹H-NMR-Untersuchungen über die Wechselwirkung von ATP mit Mg²⁺, Ca²⁺ und Monoaminen / ³¹P-and ¹H-NM R-Investigations about the Interaction of ATP with Mg²⁺, Ca²⁺, and Monoamines

Abstract

The interaction between aromatic amines and ATP is based upon an electrostatic attraction of the protonated amino groups to the negatively charged phosphate groups of ATP combined with a stacking association between the ring systems. The complexes formed are relatively weak (asociation constants 4-48 M-1), shortlived (life time smaller than 0.02 s), and mainly 1:1 in stoichiometry preferring the terminal phosphate of ATP as the site of association. The divalent metal ions Mg2+ and Ca2+ bond stronger than the amines (association constants 1500 and 100 M-1, resp.) prefer the β-phosphate group changing thereby the geometry of the ATP phosphate chain. Thus, they reduce the amine-ATP association in ternary mixtures.