Table 3.

VEGF189 bound to NRP1 with higher affinity, as compared with VEGF165

VEGF	Kon	Koff	Ka	Kd
VEGF189	14 × 105	1,7 × 10−4	82 × 108	1,2 × 10−10
VEGF165	5 × 105	6,0 × 10−4	8 × 108	1,2 × 10−9

The association and dissociation constants were measured using a BIAcore sensor approach, as described in Materials and Methods. The experiments were repeated at least twice for each concentration of protein. The affinity of NRP1 binding to VEGF165 or VEGF189 was calculated from the on and off rates. We used the steady-state analysis to estimate the affinity of NRP1 for VEGF.