Figure 6.

The effect of E189D on [³H]Ryanodine binding to RyR2. [³H] ryanodine binding to cell lysate prepared from HEK293 cells transfected with RyR2 wt (open circle) or E189D (closed triangle) cDNA was performed at: (A) various Ca²⁺ concentrations (0.2 nM to 0.1 mM), 100 mM KCl and 5 nM [³H]ryanodine. (B) Various KCl concentrations (50 to 1,000 mM), 3 nM Ca²⁺ and 5 nM [³H]ryanodine. Amounts of [³H]ryanodine binding at various KCl concentrations were normalized to the maximal binding measured in the presence of 800 mM KCl and 100 µM Ca²⁺. (C) Various caffeine concentrations (0.01 to 20 mM), 43 nM Ca²⁺ and 100 mM KCl. Data points shown are mean ± SEM from 3 or 5 separate experiments.