Figure 4

The binding affinity between soluble CAR domains and fibre knobs was characterized by surface plasmon resonance (SPR). The experimental curves (red lines) were fit using a 1:1 binding model (black lines). The equilibrium dissociation constant (Kd) was calculated by Biacore X100 Evaluation software. The results were calculated from the sensorgrams. The S.E. did not exceed 15% of the Kd.