RELATIONSHIP BETWEEN FORMATION OF HELICAL BILAYER-MEMBRANES AND CHEMICAL STRUCTURES OF DIALKYL AMPHIPHILES WITH POLYPEPTIDE-HEAD GROUP

Double-chain alkyl amphiphiles with poly(L-Asp), copoly(L-Asp-Ala), poly(L-Glu), poly(N-aminoethyl-L-glutamine), poly(L-Lys), and poly(L-Orn) as hydrophilic head groups were synthesized in order to investigate the relationship between the aggregate morphology and the chemical structure of peptide chains. The every amphiphiles were dispersed in water to form helical bilayers with metamorphosis. The CD spectra and electron microscopic observations indicated that the formation of helical aggregates closely related to the content of secondary structures in content of secondary structures influenced the molecular shapes and solubilities required to form and maintain the large curvatures of helical aggregates. In addition, morphology of the helical aggregate from poly(L-Asp) derivatives was changed on being mixed with some additives. For example, 2C-12Gln-Asp4 or 2C-12Gln-Asp12 form fragmented helices or twisted filaments spontaneously. These morphologies changed to develop helices and unilamellar vesicles by addition of 3C-12trisC-10N+ and cholesterol, respectively.