title: A membranotropic region in the C-terminal domain of hepatitis C virus protein NS4B interaction with membranes.
abstract: We have identified a membrane-active region in the HCV NS4B protein by studying membrane rupture induced by a NS4B-derived peptide library on model membranes. This segment corresponds to one of two previously predicted amphipathic helix and define it as a new membrane association domain. We report the binding and interaction with model membranes of a peptide patterned after this segment, peptide NS4B(H2), and show that NS4B(H2) strongly partitions into phospholipid membranes, interacts with them, and is located in a shallow position in the membrane. Furthermore, changes in the primary sequence cause the disruption of the hydrophobicity along the structure and prevent the resulting peptide from interacting with the membrane. Our results suggest that the region where the NS4B(H2) is located might have an essential role in the membrane replication and/or assembly of the viral particle through the modulation of the replication complex. Our findings therefore identify an important region in the HCV NS4B protein which might be implicated in the HCV life cycle and possibly in the formation of the membranous web.
authors.affiliation: Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, E-03202, Elche-Alicante, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Guillén
authors.forename: Alejandro
authors.initials: A
authors.lastname: González-Alvarez
authors.forename: José
authors.initials: J
authors.lastname: Villalaín
mesh_terms: D000595:Amino Acid Sequence; D016880:Anisotropy; D002152:Calorimetry, Differential Scanning; D005452:Fluoresceins / Q000378:metabolism; D005453:Fluorescence; D016174:Hepacivirus / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D012996:Solutions; D013055:Spectrophotometry, Infrared; D014364:Tryptophan / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D005452:Fluoresceins; D008567:Membranes, Artificial; C080107:NS4B protein, flavivirus; D010455:Peptides; D012996:Solutions; D017361:Viral Nonstructural Proteins; C024098:6-carboxyfluorescein; D014364:Tryptophan