Circular Dichroism Studies of 6‐N‐Methylated Adenylyladenosine and Adenylyluridine and Their Parent Compounds

Abstract

The temperature dependence of the circular dichroism spectra of 2 adenylyladenosine and 3 adenylyluridine dinucleotides in aqueous solution were studied. The effect of methylation of the N-6 position of the adenylyl moieties on the thermodynamic parameters of the stacking equilibrium was investigated, applying a 2-state model for the thermodynamic analysis of the experimental data. The methylated compounds allow a more accurate analysis of the data, and methylation stabilizes the stacking interaction by a relative decrease of the entropy of unstacking.