[Gene expression and activities analysis of a new fusion protein (RGD) 3/tTF]

To develop a new fusion protein (RGD)3/tTF for the therapy of the selective thrombosis of tumor blood vessels. The fused gene (RGD) 3/tTF was reconstructed by PCR, was cloned into vector pET22 b(+), and expressed in E. coli BL21 (DE3). The fusion protein was purified through Nickel-affinity chromatography column. The tTF activity of the fusion protein was detected by clotting assay and F X activation assay. The specific binding of (RGD) 3/tTF to alphavbeta3 was analyzed by indirect ELISA. The recombinant plasmid pET22 b(+)/(RGD)3/tTF was obtained and expressed in E. coli BL21 (DE3). The purified fusion protein could induce blood coagulation, activiate F X. The ability of (RGD) 3/tTF binding specifically to alphavbeta3 was increased by 32%, compared with RGD/tTF. A new fusion protein (RGD) 3/tTF was successfully expressed in E. coli BL21 (DE3). The expressed proteins retained tTF activity and showed a higher binding to alphavbeta3 than that of RGD/tTF.