P. K. Nandi

Interaction of amino acids, N-acetyl amino acid esters, thymine and adenine with sephadex LH-20 gel.

N-Acetyl aromatic amino acid esters, tryptophan, adenine and thymine show strong retention in Sephadex LH-20 gel in an aqueous phase. The decreased retention in 6 M urea, the absence of retention in absolute methanol and the increased retention at higher temperatures in the aqueous phase indicate that hydrophobic interaction is responsible for the observed retention of the amino acids and their esters in the gel. Adenine was found to be retained by polar interaction in the gel. The increased retention of the solutes in the presence of different electrolytes suggests that the lyotropic effect is more important than the ionic strength effect. The relevance of the results obtained with amino acids and esters to the conformational aspects of proteins in aqueous solution is discussed.

Studies on the interaction between small molecules by gel filtration in sephadex LH-20

Abstract A method for the study of the interaction between small molecules by gel filtration is described, based on the difference in the retention of the reactants and product in Sephadex LH-20 gel. The interaction between the anionic detergent sodium dodecyl sulphate and methylene blue and tryptophan in acidic solution is described.