Abstract: Objective To obtain 1-4 IgG-like domains of mouse vascular endothelial growth factor receptor 2 (VEGFR2) fusion
protein (mVEGFR2D1-4/GST) and identify its antiginicity and biological activity. Methods The gene of mVEGFR2D1-4 was
amplified by RT-PCR from 14-days embryos of Balb/c mice. The PCR product was cloned into pET-42a prokaryotic expression
vector to construct the recombinant plasmid pET-42a-mVEGFR2D1-4, which was transformed into E. coli BL21 (DE3) strain for
mVEGFR2D1-4/GST expression. The fusion protein was identified by SDS-PAGE and Western blotting, and the antigenicity of
the protein purified by affinity chromatography was characterized by ELISA. The VEGF blocking effect of the purified protein
in human umbilical vein endothelial cells (HUVECs) were evaluated in in vitro cell cultures. Results The mVEGFR2D1-4 gene
was obtained, which had an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for
mVEGFR2D1-4 was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting
and ELISA demonstrated the antigenicity of the purified mVEGFR2D1-4 fusion protein, which obviously blocked the effect of
VEGF in promoting HUVEC proliferation in vitro. Conclusion The mVEGFR2D1-4/GST fusion protein obtained shows a
strong antigenicity and biological activity to facilitate further study of active anti-tumor immunotherapy targeting VEGFR2.