Solid-phase synthesis of the exposed capsid peptide VP2(96-107) of the hepatitis a virus. Study of its physicochemical interactions with phospholipids

The synthesis on a solid support of a dodecapeptide containing a HAV-VP2 exposed sequence is described. The surface activity of this peptide as well as its miscibility and interactions with dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylethanolamine (DPPE), and phosphatidylinositol (PI) were determined. Interaction energies calculated applying the Gibbs equation gave very small values, thus suggesting either ideal miscibility or weak interactions. In all cases the electrical charge in DPPE and PI monolayers seems to create a high electrostatic potential, decreasing its interaction with any external molecule. This peptide was able te accommodate a certain amount of anilinonaphthalenesulfonate molecules, showing an intermediate hydrophobic character. Moreover, after incubation with saturated liposomes, the peptide showed a clear rigidifying effect at the level of polar heads, especially at temperatures under the transition temperature.