Identification of the Membrane-active Regions of Hepatitis C Virus p7 Protein: BIOPHYSICAL CHARACTERIZATION OF THE LOOP REGION

• Published in: The Journal of biological chemistry 2008-03, Vol.283 (13), p.8089-8101
• Main Authors: Pérez-Berná, Ana J, Guillén, Jaime, Moreno, Miguel R, Bernabeu, Angela, Pabst, Georg, Laggner, Peter, Villalaín, José
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Cell Membrane - drug effects; Cell Membrane - metabolism; Hepacivirus - chemistry; Hepacivirus - genetics; Hepatitis C virus; Magnetic Resonance Spectroscopy; Molecular Sequence Data; Peptide Fragments - chemistry; Peptide Fragments - pharmacology; Thermodynamics; Viral Proteins - chemistry; Viral Proteins - genetics; Viral Proteins - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M709413200

We have identified the membrane-active regions of the hepatitis C virus p7 protein by performing an exhaustive study of membrane rupture, hemifusion, and fusion induced by a p7-derived peptide library on model membranes having different phospholipid compositions. We report the identification in p7 of a highly membranotropic region located at the loop domain of the protein. Here, we have investigated the interaction of a peptide patterned after the p7 loop (peptide p7L), studying its binding and interaction with the lipid bilayer, and evaluated the binding-induced structural changes of the peptide and the phospholipids. We show that positively rich p7L strongly binds to negatively charged phospholipids and it is localized in a shallow position in the bilayer. Furthermore, peptide p7L exhibits a high tendency to oligomerize in the presence of phospholipids, which could be the driving force for the formation of the active ion channel. Therefore, our findings suggest that the p7 loop could be an attractive candidate for antiviral drug development, because it could be a target for antiviral compounds that may lead to new vaccine strategies.