title: [The biological function of auto-induced expression of the hepatitis C virus soluble core protein].
abstract: OBJECTIVE
  To investigate the biological role of auto-induced expression of hepatitis C virus (HCV) core protein (protein C) using a recombinant protein in an in vitro cell-based system.
  
  
  METHODS
  The PCR-amplified full-length HCV protein C gene (573 bp) was inserted into the pET28a prokaryotic expression vector. The recombinant plasmid was transformed into BL21(DE3)pLysS E. coli to achieve high-concentration expression of the recombinant C protein by auto-induction. The recombinant protein C was purified by Ni-NTA affinity chromatography, and tested in a protein binding assay for its ability to bind the HCV NS3 protein.
  
  
  RESULTS
  The transformed E. coli produced a large amount of recombinant protein C, as detected in the sonicated supernatant of the bacteria culture. The antigenic reactivity of the recombinant protein C was confirmed by western blotting. However, the recombinant protein C could not be purified by Ni-NTA affinity chromatography, but co-precipitated with the HCV NS3 protein.
  
  
  CONCLUSIONS
  Soluble recombinant protein C was successfully expressed by auto-induction, and shown to interact with the HCV NS3 protein, which provides a novel insight into the putative biological activity of this factor in HCV-related molecular processes. Future studies of this recombinant HCV protein C's crystal structure and antigenicity may provide further clues to its biological function(s) and potential for clinical applications.
authors.affiliation: Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Edition, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Xu-yang
authors.initials: XY
authors.lastname: Gong
authors.forename: Qi-huan
authors.initials: QH
authors.lastname: Ma
authors.forename: Xi
authors.initials: X
authors.lastname: DU
authors.forename: Jie-li
authors.initials: JL
authors.lastname: Hu
authors.forename: Xue-fei
authors.initials: XF
authors.lastname: Cai
authors.forename: Ai-long
authors.initials: AL
authors.lastname: Huang
mesh_terms: D004926:Escherichia coli / Q000378:metabolism; D005822:Genetic Vectors; D016174:Hepacivirus; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D014758:Viral Core Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000378:metabolism; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D011994:Recombinant Proteins; D014758:Viral Core Proteins; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C069130:nucleocapsid protein, Hepatitis C virus