Figure 8.

Disruption of complexes between CaM and its targets on cerebral microsomes by SPC. A) Spectra of 0.2 μM Ca²⁺-saturated dansyl-CaM alone (dotted trace), with 100 μM SPC (broken trace), with 0.5 mg/ml microsomal protein (solid trace), with 0.5 mg/ml microsomal protein and 100 μM SPC (○), with 0.5 mg/ml microsomal protein and 100 μM LPC (▵) and with 0.5 mg/ml microsomal protein and 100 μM LPA (▿). Spectra are representatives of three separate measurements. B) Concentration dependence of the complex dissociating ability of SPC. Ca²⁺-saturated dansyl-CaM and microsomal protein concentrations were 0.2 μM and 0.5 mg/ml, respectively. Fitting a sigmoidal dose-response function yielded an IC₅₀ value of 94.4 ± 2.2 μM. Data points depict means ± se (n=3).