Self-assembling properties of synthetic peptidic lipids.

Novel peptidic lipids were synthesized by the coupling of a linear oligopeptide as the hydrophilic moiety with a glutamic acid dialkylamide as the hydrophobic moiety. Their self-assembling properties were investigated. The critical aggregate concentrations (CAC) for the peptidic lipids with a double dodecyl group were in the range of 1.0 x 10(-5)-3.8 x 10(-5) M. The phase transition parameters and the aggregation morphologies in aqueous dispersion were largely dependent on the number and nature of the constitutive amino acid residues. Dark-field optical microscopy demonstrated that the present peptidic lipids can form four types of stable morphologies in water, i.e., tubular structures, twisted ribbons, vesicles, and amorphous crystals.