CONFORMATIONAL BEHAVIOR OF THE HAV-VP3(110-121) PEPTIDIC SEQUENCE ANDSYNTHETIC ANALOGS IN MEMBRANE ENVIRONMENTS STUDIED BY CD AND COMPUTATIONAL METHODS

The present study was undertaken to examine the structural features th at may be important to explain the immunogenicity of the (110-121) pep tide sequence (FWRGDLVFD-FQV) of VP3 capsid protein of hepatitis A vir us. A conformational analysis of the preferred conformations by CD and molecular mechanics was carried out. Present results suggest that the interaction with liposomes as biomembrane model induces and stabilize s the amphipathic beta-structure of the peptide.To study the contribut ion of amino acid replacements at the RGD tripeptide as well as the in fluence of the peptide chain length on peptide conformation, solid-pha se peptide synthesis of several peptide analogs was carried out and th e peptide conformation was studied using CD spectroscopy. The results show that the RGD sequence is necessary to induce the beta-structure i n the presence of liposomes. (C) 1998 John Wiley & Sons, Inc.