Screening and characterization of inhibiting peptides binding to the tumor vascular growth factor receptor
Objective To screen the phage-epitope library to predict the receptor recognition site on VEGF,identify peptide that is able to block the interaction of VEGF-KDR and to find a potent vaccine against tumor angiogenesis through targeting VEGF. Methods Two phage-epitope libraries were screened with two anti-VEGF neutralizing monoclonal antibodies JH121 and VG189. The clones were tested by Dot blot and the positive clones were used to immunize mice. The serum, phage peptides and 7-mer peptide(GWYYDAL) were added to measure their effects on the growth of HUVEC(human umbilical vascular endothelial cell). Results All the selected clones gave strong signal in Dot blot. The 7-mer peptide and 12-mer peptide selected from the peptide library elicited strong anti-VEGF antibody immuno-reaction in mice. The antibody induced by peptide GWYYDAVL abolished VEGF-induced HUVEC growth. Moreover, the peptide GWYYDAL, VASAVFYSALVE displaying on phage and the synthetic peptide, also inhibited the growth of HUVEC. Conclusion Our results suggested that the two peptides GWYYDAL and VASAVFYSALVE were both effective mimickers of VEGF and might function as potent inhibitors of KDR.