Expression and purification of invasion plasmid antigen C of Shigella flexneri.
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.
Sun
Su-xia
SX
Department of Epidemiology, First Military Medical University, Guangzhou 510515, China. suxiasun@hotmail.com
Wang
Hong
H
Wang
Yong
Y
Xiang
Qian
Q
Wu
Ai-jun
AJ
Yu
Shou-yi
SY
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*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D011994:Recombinant Proteins; C092342:IpaC protein, Shigella