title: Expression and purification of invasion plasmid antigen C of Shigella flexneri.
abstract: OBJECTIVE
  To induce the expression of and purify invasion plasmid antigen C (IpaC) of Shigella flexneri for studying the pathogenesis of Shigella flexneri.
  
  
  METHODS
  Prokaryotic expression plasmid pET32a-ipaC was constructed and incorporated into E.coli BL21 (lambda DE3). The engineered bacteria were induced by isopropyl-beta-D-thiogalactopyranoside (IPTG) to express IpaC, which was identified by SDS-PAGE and purified by QIA expressionist system.
  
  
  RESULTS
  SDS-PAGE presented a band for the fusion protein with the relative molecular mass of approximately 63 000, whose expression reached up to 11% of the total protein of E.coli BL21(lambda DE3). After proper purification, a purity of the target fusion protein of over 90% was achieved when the concentration of imidazole for elution was 350 mmol/L.
  
  
  CONCLUSIONS
  The recombinant plasmid pET32a-ipaC has been stably and efficiently expressed in E.coli BL21 (lambda DE3), and QIA expressionist purification system proves to be simple and highly efficient.
authors.affiliation: Department of Epidemiology, First Military Medical University, Guangzhou 510515, China. suxiasun@hotmail.com
authors.forename: Su-xia
authors.initials: SX
authors.lastname: Sun
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Xiang
authors.forename: Ai-jun
authors.initials: AJ
authors.lastname: Wu
authors.forename: Shou-yi
authors.initials: SY
authors.lastname: Yu
mesh_terms: D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis; D012763:Shigella flexneri / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D011994:Recombinant Proteins; C092342:IpaC protein, Shigella