BINDING OF AMINO-ACIDS TO THE CATIONIC SURFACTANT CETYLTRIMETHYLAMMONIUMBROMIDE

The interaction of amino acids with the cationic surfactant cetyltrime thylammoniumbromide (CTAB) was studied by charge transfer reversed-pha se thin-layer chromatography and the relative strength of interaction was calculated. In the majority of cases the surfactant has a negligib le effect on the hydrophobicity of amino acids. Only the binding of Ar g, Glu, Gly, Leu, Lys, Met, Nle, Phe Trp, Tyr and Val to the surfactan t was observed, however, the strength of interaction was fairly low. T he hydrophobicity of the amino acid side chains significantly influenc ed the strength of interaction. The findings support the hypothesis th at the binding of cationic surfactants to proteins involves more than one amino acid residues and that the hydrophobic forces have a conside rable impact on the interaction.