Synthesis, Expression And Characterization Of VEGF Receptor-binding Inhibitory Peptide

Object: To synthesize inhibitory peptide of VEGFR and express the peptide's fusion protein with the ability to block the interaction of VEGF-VEGFR and inhibit the proliferation of HUVEC.Methods: The 7-mer inhibitory peptide was achieved from a phage-epitope library panned with anti-VEGF neutralizing monoclonal antibodies, the peptide was synthesized and its inhibition rate for the proliferation of HUVEC was tested. The gene of 7-mer peptide was cloned and the expression plasmid pET-32a(+)_Trx_RBIP was constructed. The expression product was purified by Ion exchange chromatography and cleaved with enterokinase, followed by Ni~+ affinity chromatography purification. The inhibitory function of the final product "Trx-RBIP" was tested by cell culture.Results: The 7-mer synthetic inhibitory peptide could inhibit the growth of HUVEC with the maximum inhibitory rate 56.2%. The expression plasmid (pET-32a(+)_Trx_RBIP) was constructed successfully, and the soluble protein was expressed in E.coli and accounted for more than 40% of the total bacteria protein. The final product "Trx-RBIP" was successfully purified and tested by cell culture with the inhibitory rate 24.9% for the proliferation of HUVEC.Conclusion : This synthetic inhibitory peptide and the fusion protein "Trx-RBIP" could be potent inhibitory peptide for VEGF receptor, and block the signal transduction between VEGF-VEGFR, inhibit the proliferation of HUVEC.