[<sup>3</sup>H]S107 binding to SR vesicles.

<p>SR vesicles with low and high B<sub>max</sub> of [<sup>3</sup>H]ryanodine binding were obtained as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054208#s2" target="_blank">Materials and Methods</a>. B<sub>max</sub> of [<sup>3</sup>H]ryanodine binding was obtained as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054208#pone.0054208.s002" target="_blank">Fig. S2A</a>. Shown are the amounts of [<sup>3</sup>H]ryanodine specifically bound to SR vesicles after 5 h at 24°C. Specific [<sup>3</sup>H]S107 binding to SR vesicles was determined at 44 µM [<sup>3</sup>H]S107 and indicated free Ca<sup>2+</sup> concentration as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054208#pone.0054208.s002" target="_blank">Fig. S2B</a>. Shown are the amounts of S107 specifically bound to SR vesicles after 9 h incubation at 24°C. Data are the mean ± SD of 3–6 determinations.</p>