MICELLE FORMATION OF N-DECANOYLGLYCINE AND N-DECANOYL-L-ALANINE OLIGOMER POTASSIUM-SALTS AND THE MICELLAR STRUCTURE - A SMALL-ANGLE NEUTRON-SCATTERING STUDY

Potassium salts of N-decanoylglycine and N-decanoyl-L-alanine oligopep tides (monomer, dimer and trimer) were synthesized. For these oligomer salts in aqueous solutions, the microstructures of micelles have been investigated by small-angle neutron-scattering (SANS). In the calcula tion of SANS intensity data, the thickness of the hydrophilic layer wa s altered by changing the conformation of the oligomer moiety (helical and beta-sheet structures). For micelles of the trimer salts, the hel ical structure models provide the best fit to the observed SANS intens ity data. For micelles of the monomer- and dimer-salts, the beta-sheet model provides the best fit to the observed data. For the monomer- an d dimer-micelles, the aggregation number (n) is not dependent on the s pecies of amino acid residue, implying that the decanoyl group plays a critical role in micelle formation. However, for the trimer micelles, the n value is dependent on the species of amino acid residue.