Physicochemical interaction of a lipophilic derivative of HAV antigen VP3(110–121) with lipid monolayers

The synthesis of a palmitoyl derivative of a peptide corresponding to the HAV-VP3(110–121) sequence is described. Physicochemical characterisation was carried out through its surface activity, penetration in monolayers and influence in the miscibility of DPPC/DPPG and DPPC/SA monolayers. This peptide showed a lower surface activity than its parent, non acylated sequence. This fact is attributed to its tendency to form aggregates in water media. The thermodynamic parameters associated to the miscibility of lipids with or without peptide have been calculated, indicating that the energies involved are very low. This implies that the peptide sequence can be inserted to monolayers by means of extension bilayers without altering the packing of these lipids. It was not possible to know if these mixed monolayers were completely miscible or not due to the lack of collapse points in the compression isotherms.