Fig. 1

a Chemical structure of UniPR1331. b SPR sensorgrams showing the binding of UniPR1331 (40 μM) to the VEGFR2-Fc-coated or to the control Fc-coated surfaces. c Blank-subtracted SPR sensorgrams derived from injection of UniPR1331 on the VEGFR2-Fc surface. d Steady-state analysis obtained by Scatchard’s plot analysis of the bound RU values at equilibrium from b. White dot represents UniPR1331 binding to a control VEGF-coated surface. e ELISA-based competition experiments: inhibition curves of the binding of biotinylated ephrin-A1-Fc or VEGF to immobilized EphA2-Fc and VEGFR2 ectodomain by UniPR1331. Data in b–d are representative of other three experiments that gave similar results. Data in e are expressed as percent of binding in respect to control without inhibitor and are the mean ∓ S.E.M. of 3–6 independent experiments. f Modeled structure of the UniPR1331/VEGFR2 complex from the final frames of MD showing the key residues involved in the interaction. D2–D3 domain of VEGFR2 is depicted in white cartoons representations. VEGFR2 residues involved in the interaction and UniPR1331 are shown in gray and magenta sticks (oxygen in red, nitrogen in blue). Hydrophilic (H-bonds and salt links) and hydrophobic interactions are indicated with yellow dashed and green dotted lines.