ABSTRACT

Synthetic vaccines based on peptide immunogens provide high purity, defined structure and safety in comparison to biological vaccines. However, weaker immune responses than those elicited by intact viruses or proteins are induced. Immunogenicity can be enhanced by administering the peptides in association with carriers, lipophilically derivatised, in multiple antigenic forms or in liposomes. To use these structures as immunogens, it is convenient to know how they interact with biological membranes. Due to its complexity phospholipid mono and bilayers can provide a good biomembrane model to study these interactions. In the present work physicochemical studies of hepatitis A virus related peptides were carried out using monolayers as membrane models. Compression isotherms, surface activity and penetration kinetics into phospholipid monolayers were determined. Moreover, changes in the fluidity of bilayers induced by these peptides were analysed by means of polarizable probes.