title: Hepatitis C virus (HCV) E1 and E2 protein regions that specifically bind to HepG2 cells.
abstract: OBJECTIVE
  Identify hepatitis C virus (HCV) sequences in E1 and E2 protein binding to HepG2.
  
  
  METHODS
  Synthetic 20-mer long, ten-residue overlapped peptides, from E1 and E2 proteins, were tested in HepG2 or Raji cell-binding assays. Affinity constants, binding site number per cell and Hill coefficients were determined by saturation assay for high activity binding peptides (HABPs). Receptors for HepG2 cell were determined by cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.
  
  
  RESULTS
  Twelve HABPs were found in HCV genotype 1a, allowing six hepatocyte-binding sequences (HBSs) to be defined: two peptide-binding regions in E1 HABPs 4913 (YQVRNSTGLYHVTNDCPNSS) and 4918 (MTPTVATRDGKLPATQLRRHY). Four hepatocyte-binding regions were defined in E2: region-I, peptide 4931 (ETHVTGGSAGHTVSGFVSLLY); region-II, 4937-4939 (HHKFNSSGCPERLASCRPLTDFDQGWGPISYANGSGPDQR); region-III, 4943-4945 (PVYCFTPSPVVVGTTDRSGAPTYSWGENDTDVFVLNNTR) and region-IV, 4949-4952 (CGAPPCVIGGAGNNTLHCPTDCFRKHPDATYSRCGSGPWITPRCLVDYPY). The underlined sequences are most relevant in the binding process. HABPs 4913 and 4938 also bind to CD81 positive Raji cells. Region-II 4938 HABPs bind to 50 and 60kDa HepG2 cell membrane surface proteins.
  
  
  CONCLUSIONS
  Six HVRs to the HepG2 were identified. Some HABPs have been previously found to be antigenic and immunogenic. HABPs, 4918 (from E1), 4938, 4949, 4950, 4951 and 4952 (from E2) have not been previously recognised. These HABPs could be relevant to HCV invasion of hepatocytes.
authors.affiliation: Fundación Instituto de Inmunologia de Colombia, Universidad Nacional de Colombia, Avda. Calle 26 No. 51-60 Bogota, Colombia. javgar22@hotmail.com
authors.forename: Javier Eduardo
authors.initials: JE
authors.lastname: Garcia
authors.forename: Alvaro
authors.initials: A
authors.lastname: Puentes
authors.forename: Jorge
authors.initials: J
authors.lastname: Súarez
authors.forename: Ramses
authors.initials: R
authors.lastname: López
authors.forename: Ricardo
authors.initials: R
authors.lastname: Vera
authors.forename: Luis Eduardo
authors.initials: LE
authors.lastname: Rodríguez
authors.forename: Marisol
authors.initials: M
authors.lastname: Ocampo
authors.forename: Hernando
authors.initials: H
authors.lastname: Curtidor
authors.forename: Fanny
authors.initials: F
authors.lastname: Guzman
authors.forename: Mauricio
authors.initials: M
authors.lastname: Urquiza
authors.forename: Manuel Elkin
authors.initials: ME
authors.lastname: Patarroyo
mesh_terms: D000595:Amino Acid Sequence; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000821:virology*; D006801:Humans; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000235:genetics; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000821:virology; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C087035:E1 protein, Hepatitis C virus; C400562:HVR1 protein, Hepatitis C virus; D007457:Iodine Radioisotopes; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C091015:glycoprotein E2, Hepatitis C virus