title: Interaction of hepatitis C virus envelope glycoprotein E2 with the large extracellular loop of tupaia CD81.
abstract: OBJECTIVE
  To further analyze the interaction of tupaia CD81 with hepatitis C virus (HCV) envelope protein E2.
  
  
  METHODS
  A tupaia CD81 large extracellular loop (CD81 LEL), which binds to HCV E2 protein, was cloned and expressed as a GST-fusion protein, and interaction of HCV E2 protein with a tupaia CD81 LEL was evaluated by enzyme-linked immunosorbent assay (EIA).
  
  
  RESULTS
  Although tupaia and human CD81 LEL differed in 6 amino acid changes, tupaia CD81 LEL was strongly recognized by anti-CD81 antibodies against human CD81 LEL conformation-dependent epitopes. Investigating LEL CD81-E2 interactions by EIA, we demonstrated that binding of tupaia CD81 LEL GST fusion protein to recombinant HCV E2 protein was markedly reduced compared to binding of human CD81 LEL GST fusion protein to recombinant HCV E2 protein.
  
  
  CONCLUSIONS
  These data suggest that the structural differences in-between the tupaia and human CD81 may alter the interaction of the large extracellular loop with HCV envelope glycoprotein E2. These findings may be important for the understanding of the mechanisms of binding and entry of HCV to PTHs.
authors.affiliation: Department of Infectious Diseases, 161 Hospital of PLA, Wuhan 430030, Hubei Province, China.
authors.forename: Zhan-Fei
authors.initials: ZF
authors.lastname: Tian
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Xi-Hua
authors.initials: XH
authors.lastname: Fu
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chen
authors.forename: Hubert E
authors.initials: HE
authors.lastname: Blum
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Baumert
authors.forename: Xi-Ping
authors.initials: XP
authors.lastname: Zhao
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D016174:Hepacivirus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D022781:Hepatocytes / Q000378:metabolism / Q000821:virology; D054884:Host-Pathogen Interactions; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D060225:Tetraspanin 28; D014417:Tupaia / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; C554798:CD81 protein, human; D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus