Expression and characterization of Escherichia coli derived hepatitis C virus ARFP/F protein

Mol Biol (Mosk). 2012 Mar-Apr;46(2):251-9.

Abstract

Genome of the hepatitis C virus (HCV) contains a long open reading frame encoding a polyprotein that is cleaved into 10 proteins. Recently, a novel, so called "ARFP/F", or "core+1", protein, which is expressed through a ribosomal frame shift within the capsid-coding sequence, has been described. Herein, to produce and characterize a recombinant form of this protein, the DNA sequence corresponding to the ARFP/F protein (amino acid 11-161) was amplified using a frame-shifted forward primer exploiting the capsid sequence of the 1b-subtype as a template. The amplicon was cloned into the pET-24a vector and expressed in different Escherichia coli strains. The expressed protein (mostly as insoluble inclusion bodies) was purified under denaturing conditions on a nickel-nitrilotriacetic acid (Ni-NTA) affinity column in a single step with a yield of 5 mg/L of culture media. After refolding steps, characterization of expressed ARFP/F was performed by SDS-PAGE and Western blot assay using specific antibodies. Antigenic properties of the protein were verified by ELISA using HCV-infected human sera and by its ability for a strong and specific interaction with sera of mice immunized with the peptide encoding a dominant ARFP/F B-cell epitope. The antigenicity plot revealed 3 major antigenic domains in the first half of the ARFP/F sequence. Immunization of BALB/c mice with the ARFP/F protein elicited high titers of IgG indicating the relevance of produced protein for induction of a humoral response. In conclusion, possibility of ARFP/F expression with a high yield and immunogenic potency of this protein in a mouse model have been demonstrated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / immunology
  • Epitopes, B-Lymphocyte* / biosynthesis
  • Epitopes, B-Lymphocyte* / genetics
  • Epitopes, B-Lymphocyte* / immunology
  • Epitopes, B-Lymphocyte* / isolation & purification
  • Epitopes, B-Lymphocyte* / pharmacology
  • Escherichia coli
  • Gene Expression
  • Hepacivirus / genetics
  • Hepacivirus / immunology
  • Humans
  • Immunization
  • Immunoglobulin G / immunology
  • Mice
  • Mice, Inbred BALB C
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / pharmacology
  • Viral Core Proteins* / biosynthesis
  • Viral Core Proteins* / genetics
  • Viral Core Proteins* / isolation & purification
  • Viral Core Proteins* / metabolism
  • Viral Core Proteins* / pharmacology

Substances

  • Antibodies, Viral
  • Epitopes, B-Lymphocyte
  • Immunoglobulin G
  • Recombinant Proteins
  • Viral Core Proteins
  • hepatitis C protein F, Hepatitis C virus