Phage-derived fully human antibody scFv fragment directed against human vascular endothelial growth factor receptor 2 blocked its interaction with VEGF.

Zhang, Juan; Li, Haixin; Wang, Xiuyun; Qi, Haidi; Miao, Xiaoniu; Zhang, Tao; Chen, Guosheng; Wang, Min

Vascular endothelial growth factor receptor 2 (VEGFR-2) plays a critical role in tumor angiogenesis. None therapeutic antibodies targeting VEGFR-2 are available in clinical use. Herein, we describe the screening of a new single-chain antibody fragment (scFv) targeting extracellular domain 3 of human VEGFR-2 (kinase insert domain-containing receptor [KDR]3) from Griffin phage display scFv library. A comprehensive sequence analysis was performed to assign the framework and complementary-determining regions. The scFv exerted particular binding sites to KDR3 on molecular docking, and the binding affinity was further convinced by binding analysis both in quantitative ELISA and real-time kinetic determination by biosensors (K(D) = 40 nM). Finally, the scFv was revealed to inhibit VEGF-stimulated proliferation of human umbilical vein endothelial cells (HUVECs; IC(50) = 5 nM) and to inhibit HUVEC migration significantly at 17 nM. Taken together, our results indicate that we have successfully isolated a scFv which differentially recognizes KDR3 and has potential clinical applications in the treatment of angiogenesis related diseases.