title: High yield expression in a recombinant E. coli of a codon optimized chicken anemia virus capsid protein VP1 useful for vaccine development.
abstract: BACKGROUND
  Chicken anemia virus (CAV), the causative agent chicken anemia, is the only member of the genus Gyrovirus of the Circoviridae family. CAV is an immune suppressive virus and causes anemia, lymph organ atrophy and immunodeficiency. The production and biochemical characterization of VP1 protein and its use in a subunit vaccine or as part of a diagnostic kit would be useful to CAV infection prevention.
  
  
  RESULTS
  Significantly increased expression of the recombinant full-length VP1 capsid protein from chicken anemia virus was demonstrated using an E. coli expression system. The VP1 gene was cloned into various different expression vectors and then these were expressed in a number of different E. coli strains. The expression of CAV VP1 in E. coli was significantly increased when VP1 was fused with GST protein rather than a His-tag. By optimizing the various rare amino acid codons within the N-terminus of the VP1 protein, the expression level of the VP1 protein in E. coli BL21(DE3)-pLysS was further increased significantly. The highest protein expression level obtained was 17.5 g/L per liter of bacterial culture after induction with 0.1 mM IPTG for 2 h. After purification by GST affinity chromatography, the purified full-length VP1 protein produced in this way was demonstrated to have good antigenicity and was able to be recognized by CAV-positive chicken serum in an ELISA assay.
  
  
  CONCLUSIONS
  Purified recombinant VP1 protein with the gene's codons optimized in the N-terminal region has potential as chimeric protein that, when expressed in E. coli, may be useful in the future for the development of subunit vaccines and diagnostic tests.
authors.affiliation: School of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan.
authors.forename: Meng-Shiou
authors.initials: MS
authors.lastname: Lee
authors.forename: You-Cheng
authors.initials: YC
authors.lastname: Hseu
authors.forename: Guan-Hua
authors.initials: GH
authors.lastname: Lai
authors.forename: Wen-Te
authors.initials: WT
authors.lastname: Chang
authors.forename: Hsi-Jien
authors.initials: HJ
authors.lastname: Chen
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Huang
authors.forename: Meng-Shiunn
authors.initials: MS
authors.lastname: Lee
authors.forename: Min-Ying
authors.initials: MY
authors.lastname: Wang
authors.forename: Jung-Yie
authors.initials: JY
authors.lastname: Kao
authors.forename: Bang-Jau
authors.initials: BJ
authors.lastname: You
authors.forename: Wen- Hsin
authors.initials: W
authors.lastname: Lin
authors.forename: Yi-Yang
authors.initials: YY
authors.lastname: Lien
authors.forename: Ming-Kuem
authors.initials: MK
authors.lastname: Lin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002645:Chickens / Q000821:virology; D003062:Codon; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D005982:Glutathione Transferase / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
chemical_list: D036022:Capsid Proteins; D003062:Codon; D011993:Recombinant Fusion Proteins; C442548:VP1 protein, Chicken anemia virus; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; D005982:Glutathione Transferase