Expression
and Characterization of Hepatitis C Virus E2 Glycoprotein Fused to Hepatitis B
Virus preS1(21¡ª47) Fragment in CHO Cells
WANG Chun-Lin, ZHU Li-Xin, LIU Jing,
ZHANG Zu-Chuan, WANG Yuan*, LI Guang-Di*
( State Key Laboratory of Molecular Biology, Institute of Biochemistry
and Cell Biology, Shanghai Institutes for Biological Sciences, the Chinese
Academy of Sciences, Shanghai 200031, China )
Abstract To stably
express hepatitis C virus (HCV) E2 glycoprotein in CHO cells and facilitate the
detection and purification of the expression products, the gene fragment
encoding N-terminal 277 amino acids of this protein was fused to the fragment
encoding hepatitis B virus (HBV) preS1(21¡ª47) region and inserted into a
secretion vector pSecTagB. CHO cells transfected with the recombinant plasmid
carrying fusion gene were selected under growth pressure of Zeocin. Secreted
fusion products and its cell-associated counterpart were detected by Western
blot using E2 specific or preS1 specific antibodies. Glycans carried by the
expression products were analyzed with glycan-type specific glycosidases. Most
of the cell-associated E2 were found to be high-mannose-type glycosylated,
while the secreted E2 proteins were found to be mostly complex-type
glycosylated, suggesting further modification in Golgi apparatus upon
secretion. Primary studies showed that the fusion antigen could be specifically
bind to and elute from anti-preS1 antibody coupled Sepharose resin, suggesting
that large-scale preparation of the fusion antigen is feasible with an
immunoaffinity resin. This work will contribute to the further study of
immunological properties of HCV E2 glycoprotein and also to the study of
recombinant HBV/HCV vaccine.
Key words hepatitis C virus (HCV); hepatitis B virus
(HBV); E2 glycoprotein; preS1
*Corresponding authors: Tel, 86-21-64374430-5326; Fax, 86-21-64338357; e-mail, [email protected]