Precise Ultraviolet Absorbance Study of the Interaction of Amino Acids and Mononucleosides in Aqueous Solution

摘要

Affinity coefficients of various amino acids or their derivatives (methyl esters, amides, etc.) with mononucleosides in aqueous solutions have been measured by using a precise ultraviolet difference absorbance photometry. The results are in general agreement with those of previous solubility experiments. The superiority of this ultraviolet absorbance experiments to the solubility experiments is that this method can discriminate stacking and hydrogen bonding interactions by using the hypochromicity and hyperchromicity of the absorbance, respectively. It is also confirmed that the hydrogen bonding interactions of the side chains of the amino acids with the nucleic acid bases observed in nonaqueous hydrophobic solutions by the nuclear magnetic resonance method clearly functions in aqueous solutions. New types of specific interactions of some amino acids with nucleic acid bases by using a peptydic carboxyl radical and another radical in their side chains have been found in this experiment.