title: A Biologically-validated HCV E1E2 Heterodimer Structural Model.
abstract: The design of vaccine strategies and the development of drugs targeting the early stages of Hepatitis C virus (HCV) infection are hampered by the lack of structural information about its surface glycoproteins E1 and E2, the two constituents of HCV entry machinery. Despite the recent crystal resolution of limited versions of both proteins in truncated form, a complete picture of the E1E2 complex is still missing. Here we combined deep computational analysis of E1E2 secondary, tertiary and quaternary structure with functional and immunological mutational analysis across E1E2 in order to propose an in silico model for the ectodomain of the E1E2 heterodimer. Our model describes E1-E2 ectodomain dimerization interfaces, provides a structural explanation of E1 and E2 immunogenicity and sheds light on the molecular processes and disulfide bridges isomerization underlying the conformational changes required for fusion. Comprehensive alanine mutational analysis across 553 residues of E1E2 also resulted in identifying the epitope maps of diverse mAbs and the disulfide connectivity underlying E1E2 native conformation. The predicted structure unveils E1 and E2 structures in complex, thus representing a step towards the rational design of immunogens and drugs inhibiting HCV entry.
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Castelli
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Nicola
authors.identifier: 0000-0002-1822-9861
authors.initials: N
authors.lastname: Clementi
authors.affiliation: Integral Molecular, 3711 Market St #900, Philadelphia, PA, 19104, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pfaff
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Giuseppe A
authors.initials: GA
authors.lastname: Sautto
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Roberta A
authors.initials: RA
authors.lastname: Diotti
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Burioni
authors.affiliation: Integral Molecular, 3711 Market St #900, Philadelphia, PA, 19104, USA.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Doranz
authors.affiliation: Laboratory for Biomolecular Modeling, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Route Cantonale, 1015, Lausanne, Switzerland.|Swiss Institute of Bioinformatics, Lausanne, Switzerland.
authors.forename: Matteo
authors.initials: M
authors.lastname: Dal Peraro
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Clementi
authors.affiliation: Laboratory of Microbiology and Virology, Università "Vita-Salute" San Raffaele, Via Olgettina 58, 20132, Milano, Italy. mancini.nicasio@hsr.it.
authors.forename: Nicasio
authors.initials: N
authors.lastname: Mancini
mesh_terms: D019295:Computational Biology / Q000379:methods; D003198:Computer Simulation; D004220:Disulfides / Q000737:chemistry; D018604:Epitope Mapping; D016174:Hepacivirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D055503:Protein Multimerization; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D004220:Disulfides; C087035:E1 protein, Hepatitis C virus; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus