Human Recombinant VEGFR2D4 Biochemical Characterization to Investigate Novel Anti VEGFR2D4 Antibodies for Allosteric Targeting of VEGFR2
VEGF-A/VEGFR2 complex is the major signaling pathway involved in angiogenesis and the inhibition of this axis retards tumor growth and infammatory disorders progression, reducing vessel sprouting. Signaling by VEGFR2 requires receptor
dimerization and a well-defned orientation of monomers in the active dimer. The extracellular portion of receptor is com- posed of seven Ig-like domains, of which D2–3 are the ligand binding domains, while D4 and D7, establishing homotypic
contacts, allosterically regulate receptor activity. The allosteric targeting of VEGFR2 represents a promising alternative to study neovascular disorders overcoming drawbacks related to competition with VEGF. In this work, we expressed in bacterial host domain 4 of VEGFR2 (VEGFR2D4). After protein refolding, we characterized the purifed domain and administered it in mice for monoclonal antibodies production. One of them, mAbD4, was tested in ELISA assays, showing a nanomolar afnity for VEGFR2D4. Finally, the methodology here described could contribute to the development of antibodies which can allosterically bind VEGFR2 and therefore to be used for imaging purposes or to modulate receptor signaling.