Interaction study of peptide from VP3 capsid protein of hepatitis A virus through monolayers and fluorescence spectroscopy

A synthetic peptide with the sequence [Lys113]VP3(110-121): FWRKDLVFDFQV, c orresponding to an epitope of the VP3 capsid protein of hepatitis A virus ( HAV), was synthesized by solid phase and characterized. To obtain insight i nto its physicochemical properties and to understand its possible mechanism of action at the membrane level, interaction with DPPC or DPPC/DPPG(95/5) liposomes and lipid monolayers of DPPC, DPPG, SA, PS, PA and SM were studie d by fluorescence spectroscopy and Langmuir-Blotgett films technique, respe ctively. Fluorescence studies showed that the peptide was in a hydrophobic environment when DPPC liposomes were used. The addition of a 5% of a charge d lipid, DPPG, to the preparations changed the preference of the peptide to wards a polar surrounding. However, the peptide had a high surface activity (nmol/L) and was able to incorporate into lipid monolayers. interaction wa s higher with charged phospholipids than with neutral ones. These results m ay have physiological significance in the mechanism of infection of host he patic cells by HAV. Copyright (C) 2001 John Wiley & Sons, Ltd.