Influence of phospholipidic charge on the interaction of a multiple antigenic peptide from hepatitis a virus with monolayers and bilayers

Miscibility of dipalmitoylphosphatidylcholine (DPPC) with dipalmitoylphosphatidylglycerol (DPPG), cardiolipin (CL), and dipalmitoylphosphatidylethanolamine (DPPE) was studied using mono- and bilayers of different compositions. The influence of MAP4-VP1 peptide construct (related to hepatitis A virus protein) in mixed monolayers of the lipids above cited was determined by studying penetration kinetics and compression isotherms. Moreover, liposomes with the same composition than monolayers were saturated with sodium anilinonaphthalene sulfonate or diphenylhexatriene and incubated with MAP4-VP1; polarization values as well as transition temperatures were determined. Results in isotherm and polarization studies showed some degree of interaction between the peptide and the phospholipids assayed. DPPC/ DPPG composition showed the maximum interaction followed by DPPC/CL. The interaction was not strong, suggesting that the entrapment of MAP4-VP1 in liposomes in order to increase its immunogenic activity is possible.