title: Expression and Purification of Recombinant Hepatitis Delta Virus (HDV) Antigen for Use in a Diagnostic ELISA for HDV Infection Using the High-Density Fermentation Strategy in Escherichia coli.
abstract: OBJECTIVE
  Hepatitis Delt a Virus (HDV) antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for this purpose.
  
  
  METHODS
  Reconstruct the gene of HDV antigen based on the bias code of Escherichia coli, the recombinant protein expresses by high-density fermentation with fed-batch feeding strategy, and purify by immobilized metal chromatography. The sensitivity and specificity of this antigen detect by ELISA method.
  
  
  RESULTS
  The expression of HDV antigen can reach 20% of the total cell mass in the soluble form. The recombinant HDV antigen can be conveniently purified (98%) by immobilized metal ion affinity chromatography (IMAC) using the interaction between a His-tag and nickel ions. Production of recombinant HDV antigen can reach 0.5 g/L under conditions of high-density cell fermentation. Applied to the diagnostic ELISA method, the recombinant HDV antigen shows excellent sensitivity (97% for IgM and 100% for IgG) and specificity (100% for IgG and IgM) for the detection of anti-HDV antibodies.
  
  
  CONCLUSIONS
  Expression and purification the recombinant HDV antigen as a candidate protein for application in a diagnostic ELISA for HDV infection. Large-scale production of the protein can be achieved using the high-density fermentation strategy.
authors.affiliation: National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Xue Xin
authors.initials: XX
authors.lastname: Lu
authors.affiliation: National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yi
authors.affiliation: National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Qiu Dong
authors.initials: QD
authors.lastname: Su
authors.affiliation: National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Sheng Li
authors.initials: SL
authors.lastname: Bi
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D003699:Hepatitis D / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D003698:Hepatitis Delta Virus / Q000276:immunology*; D035923:Hepatitis delta Antigens / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D035923:Hepatitis delta Antigens; D011994:Recombinant Proteins
keywords: ELISA diagnosis; HDV; High-density cell fermentation; IMAC