Figure 5.

Ca²⁺ dissociation kinetics of CaM in the absence of peptide. Dissociation of Ca²⁺ from CaM_WT (A), CaM₁₂ (B), and CaM₃₄ (C) was measured by monitoring changes in quin-2 fluorescence. Quin-2 (150 μM) was rapidly mixed with 20 μM Ca²⁺ and 2 μM CaM. The inset of panel C shows the close-up trace of dissociation of Ca²⁺ from CaM₃₄ from 0 to 0.04 s. Each trace that represents an average of five to eight runs was fit using a single-exponential function. Data are representative of at least four experiments.