Figure 3

Surface plasmon resonance analysis of the binding of recoverin forms to an immobilized rod outer segment lipid mixture. (A) Myristoylated forms of WT recoverin (upper trace) and Rc^2–190 were injected at a concentration of 30 μM in SPR running buffer at a flow rate of 5 μl/min. Time of injection is indicated by the black bar at the top. (B) Sensorgrams showing the injection of nonmyristoylated forms of WT recoverin and Rc^2–190 into the system. Protein concentration and conditions were the same as in (A). (C) Difference signal (solid curve) obtained by subtracting sensorgram labelled Rc^2–190 from sensorgram WT shown in (A). Dashed curve repesents the fit of the difference curve to the model describing a parallel reaction on a heterogeneous ligand surface (BIAevaluation 4.1). The two corresponding association rate constants were: k_a1 = 2.29 × 10³ M^-1s^-1 and k_a2 = 0.707 × 10³ M^-1s^-1. Dissociation rate constants were k_d1 = 0.013 s^-1 and k_d2 = 0.0016 s^-1.