Fig. 4. Ca²⁺-dependent dissociation of the N_xCCaM or NC_xCaM complexes with BSCaM_IQ.

Fractional changes in 525 nm fluorescence emission associated with formation of the complexes between 12.5 μM BSCaM_IQ and 1 μM N_xCCaM (◆) or NC_xCaM (■). All free Ca²⁺ concentrations were verified using indo-5F or mag-indo-1. Fractional changes in fluorescence are defined using an F_max value measured at the end of the experiment, which accounts for residual CaM binding in the presence of Ca²⁺. Otherwise fractional changes are defined as described in the legend to Fig. 2. Apparent Ca²⁺-binding constants derived from fits of these data to equation 2 are listed in Table 2.