Purification and application of C-terminally truncated hepatitis C virus E1 proteins expressed in Escherichia coli.
OBJECTIVE
To explore the possibility of expressing hepatitis C virus (HCV) envelope protein 1 (E1) in Escherichia coli (E. coli) and to test the purified recombinant E1 proteins for clinical and research applications.


METHODS
C-terminally truncated E1 fragments were expressed in E. coli as hexa-histidine-tagged fusion proteins. The expression products were purified under denaturing conditions using immobilized-metal affinity chromatography. Purified E1 proteins were used to immunize rabbits. Rabbit anti-sera thus obtained were reacted with both E. coli- and mammalian cell-expressed E1 glycoproteins as detected by Western blot.


RESULTS
Full-length E1 protein proved difficult to express in E. coli. C-terminally truncated E1 was successfully expressed in E. coli as hexa-histidine-tagged recombinant fusion protein and was purified under denaturing conditions on Ni(2+)-NTA agarose. Rabbit anti-sera raised against purified recombinant E1 specifically reacted with mammalian cell-expressed E1 glycoproteins in Western blot. Furthermore, E. coli-derived E1 protein was able to detect animal antibodies elicited by E1-based DNA immunization.


CONCLUSIONS
These results demonstrate that the prokaryotically expressed E1 proteins share identical epitopes with eukaryotically expressed E1 glycoprotein. The E. coli-derived E1 proteins and corresponding antisera can become useful tools in anti-HCV vaccine research.
Liu
Jing
J
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Zhu
Li-Xin
LX
Kong
Yu-Ying
YY
Li
Guang-Di
GD
Wang
Yuan
Y
D000818:Animals; D000914:Antibodies, Viral; D000918:Antibody Specificity; D004926:Escherichia coli / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D016174:Hepacivirus / Q000235:genetics*; D010957:Plasmids; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D014765:Viral Vaccines / Q000235:genetics
D000914:Antibodies, Viral; C087035:E1 protein, Hepatitis C virus; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D014765:Viral Vaccines