Figure 2

Simulated binding response curves for rebinding and inhibition of rebinding. Three mass transport limited binding curves for 10 nM B binding to P tethered within a hydrogel are shown on the left. The response curves were normalized to the maximum saturation response R_max. The three simulated curves correspond to k_t values of 1 × 10⁷ s⁻¹, 1 × 10⁸ s⁻¹ and 1 × 10⁹ s⁻¹ producing Da values of 100, 10, and 1, respectively. The simulation was performed using a two-compartment model (see Methods for more details) and the interaction parameters were R_max = 20 RU, k_a′ = 5 × 10⁷ M⁻¹ s⁻¹ and k_d′ = 0.05 s⁻¹. Inhibition of rebinding during the dissociation phase at fixed operating conditions is depicted on the right, where A was injected (injection time = t₀) at 100 µM and replicated over a serial fivefold range in k_a from 1 × 10⁵ M⁻¹ s⁻¹ to 7.81 × 10⁹ M⁻¹ s⁻¹ to produce dose-dependent inhibition of rebinding. The response observed at the onset (t₀) of the inhibitor injection is R₀. Inhibition curves were simulated using the virtual instrument and finite element analysis engine described in the Method section.