Precise ultraviolet absorbance study of the interactions of amino acids and mononucleosides in aqueous solution

The association constants of various amino acids or their derivatives (methyl esters, amides, etc.) with mononucleosides in aqueous solutions have been measured by using precise ultraviolet difference absorbance photometry. Some of the results are in agreement with those of the previous solubility experiments. The superiority of this ultraviolet absorbance method over the solubility experiments is that it can discriminate between stacking and hydrogen-bonding interactions. New types of specific interactions of some amino acids with nucleic acid bases by using a peptidyl carboxylate ion and another donor or acceptor in their side chains have been found using this technique.