title: Cholesterol-Enriched Domain Formation Induced by Viral-Encoded, Membrane-Active Amphipathic Peptide.
abstract: The α-helical (AH) domain of the hepatitis C virus nonstructural protein NS5A, anchored at the cytoplasmic leaflet of the endoplasmic reticulum, plays a role in viral replication. However, the peptides derived from this domain also exhibit remarkably broad-spectrum virocidal activity, raising questions about their modes of membrane association. Here, using giant lipid vesicles, we show that the AH peptide discriminates between membrane compositions. In cholesterol-containing membranes, peptide binding induces microdomain formation. By contrast, cholesterol-depleted membranes undergo global softening at elevated peptide concentrations. Furthermore, in mixed populations, the presence of ∼100 nm vesicles of viral dimensions suppresses these peptide-induced perturbations in giant unilamellar vesicles, suggesting size-dependent membrane association. These synergistic composition- and size-dependent interactions explain, in part, how the AH domain might on the one hand segregate molecules needed for viral assembly and on the other hand furnish peptides that exhibit broad-spectrum virocidal activity.
authors.affiliation: Biophysics Graduate Group, University of California, Davis, Davis, California.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Hanson
authors.affiliation: Department of Chemical Engineering & Materials Science, University of California, Davis, Davis, California.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Gettel
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors.forename: Seyed R
authors.initials: SR
authors.lastname: Tabaei
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors.forename: Joshua
authors.initials: J
authors.lastname: Jackman
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors.forename: Min Chul
authors.initials: MC
authors.lastname: Kim
authors.affiliation: Biotechnology and Bioengineering Department, Sandia National Laboratories, Livermore, California.
authors.forename: Darryl Y
authors.initials: DY
authors.lastname: Sasaki
authors.affiliation: Chemistry Department, University of California, Berkeley, California; Mechanobiology Institute, National University of Singapore, Singapore.
authors.forename: Jay T
authors.initials: JT
authors.lastname: Groves
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Liedberg
authors.affiliation: Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore.
authors.forename: Nam-Joon
authors.initials: NJ
authors.lastname: Cho
authors.affiliation: Biophysics Graduate Group, University of California, Davis, Davis, California; Department of Chemical Engineering & Materials Science, University of California, Davis, Davis, California; Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore; Department of Biomedical Engineering, University of California, Davis, Davis, California. Electronic address: anparikh@ucdavis.edu.
authors.forename: Atul N
authors.initials: AN
authors.lastname: Parikh
mesh_terms: D000595:Amino Acid Sequence; D001696:Biomechanical Phenomena; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D016174:Hepacivirus / Q000235:genetics*; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase
chemical_list: D002784:Cholesterol; D008051:Lipid Bilayers; D010446:Peptide Fragments; D053835:Unilamellar Liposomes; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase