Expression
and Characterization of Single-chain Fv-Fc Fusion Protein
against Human P185erbB2
XIE Zhi-Gang, GUO Ning*, SHI
Ming, FENG Jian-Nan, YU Ming, SUN Ying-Xun, SHEN Bei-Fen
( Institute of Basic Medical Sciences, Academy of Military
Medical Sciences, Beijing 100850, China )
Abstract In order to increase therapeutic effects
and decrease immunogenicity of mouse McAb, the single-chain Fv (scFv) created
by fusing the light and heavy chain variable region genes of anti-human
P185erbB2 McAb was conjugated to the Fc gene of human IgG1 to
construct a scFv-Fc fusion gene. The scFv-Fc fusion gene was
cloned into the expression vector pCIDN. The scFv-Fc fusion protein was
synthesized as secreted two-chain molecules in CHO cells, and purified by
affinity chromatography on recombinant protein A. A special 185 kD P185erbB2
protein was immunoprecipitated by the scFv-Fc fusion protein. The
fluorescence-activated cell sorting (FACS) using SK-BR-3 cells as the target
indicated that the fusion protein could bind to the extracellular domain of
P185erbB2. The affinity of the scFv-Fc fusion protein, determined by
ELISA, was K=7.5´10–10 (mol/L)–1. This work laid basis for
further studies on the anti-P185erbB2 scFv-Fc fusion protein.
Key
words
Her2/neu; scFv; fusion protein
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