LIPOSOME-INDUCED CONFORMATIONAL-CHANGES OF AN EPITOPIC PEPTIDE AND ITS PALMITOYLATED DERIVATIVE OF INFLUENZA-VIRUS HEMAGGLUTININ

The conformation of synthetic HA(317-329)-NH2 representing the major B - and T-cell epitopic region of influenza virus hemagglutinin, its pal mitoylated derivative (HA(317-329)-Thr(Pal)-NH2), and the intersubunit peptide (HA(317-341)-NH2) comprising also the fusion peptide, were st udied in aqueous buffer and in the presence of neutral and negatively charged liposomes. The free peptide is unordered in aqueous solution, even in the presence of liposomes. However, grafting the palmitic acid or the fusion peptide onto the C-terminus of the peptide enables the hydrophilic HA(317-329) to adopt folded (turn) and P-strand structure on the surface of neutral and negatively charged liposomes, respective ly. The results emphasize the importance of some kind of anchor for ac hieving a specific conformation of epitopic peptide HA(317-329)-NH2 on the surface of liposomes. (C) 1998 Academic Press.