The HGF N-terminal domain competes with VEGF-A₁₆₅ for binding to NRP1. (A) Solid-phase receptor assay analysis of the binding of biotinylated VEGF-A₁₆₅ to VEGFR-2/Fc, and NRP1/Fc immobilized via the Fc moieties on plates coated with anti-Fc IgG. Bound VEGF-A₁₆₅ was detected by peroxidase-conjugated streptavidin staining. (B) Microtiter plates coated with NRP1/Fc were incubated with biotinylated VEGF-A₁₆₅ in the presence of various concentrations of N, nonmodified VEGF-A₁₆₅, or lysozyme. Values are means plus or minus SD of 3 independent experiments.