Proton magnetic relaxation of adenosine 5′-diphosphate and adenosine 5′-triphosphate in solution

Abstract

Measurements have been made of the longitudinal proton magnetic relaxation of the non-exchangeable protons of ADP and ATP in D 2O solutions at 300 MHz from 278 to 333 K. The proton spin-lattice relaxation times of both compounds are dominated by dipolar interactions. The motion of the ADP and ATP molecules in the solution and hindered intramolecular motions around the glycosidic and the C 4′C 5′ bonds are responsible for the modulation of the dipolar interactions. Activation energies characterizing the intramolecular motions range between 8.0 and 16.0 and between 19.6 and 67.9 kJ/mole respectively.