Solvent effects on the conformation of nucleotides. Part 2. Nuclear magnetic shift and relaxation effects induced by lanthanide ions on adenosine 5′-monophosphate in water–dimethyl sulphoxide
Abstract
The shift and relaxation effects on the n.m.r. spectrum of adenosine 5′-monophosphate due to binding of lanthanide(III) cations in the mixed solvent D2O–[2H6]dimethyl sulphoxide have been studied as a function of solvent composition, temperature, and addition of chaotropic agents. Relaxation time measurements show that all lanthanides form isostructural complexes with the mononucleotide. The dipolar shifts induced by the lanthanides are determined by an averaged susceptibility tensor, whose symmetry is determined by the structure and dynamics of the ion-solvation shell. This symmetry is closer to axial for lanthanides in the first half of the series than for those in the second half. A temperature increase and a decrease of [2H6]dimethyl sulphoxide mol fraction have similar effects on the symmetry of the dipolar shifts.
Please wait while we load your content...
