Fig. 4: Reduced calstabin-2 binding to the primed state of CPVT variants.
From: Structural basis for ryanodine receptor type 2 leak in heart failure and arrhythmogenic disorders
a Binding curves of calstabin-2 to WT RyR2. Concentration of calstabin-2 is 5, 10, 50, 100, 500, and 1000 nM (from black to magenta), and RyR2 is 5 nM. Reactions were performed as duplicates. Data are presented as mean values and error bars as SD. All points were simultaneously fitted using the equation Association Kinetics - Two or more concentrations of ligand in GraphPad. Fitting curves are shown in gray, R2 = 0.9895. b Table showing the values of kon, koff, and Kd derived from the association kinetics curves for the different variants of RyR2. c Table showing the correlation between the primed state conformation (“RMSD”), calstabin-2 koff, and onset age for the CPVT mutants tested (y.o.: years old)53. “RMSD” stands for the value of the normalized RMSD difference analysis of each structure. *The age of onset for WT RyR2 was considered as the average age when exercise-induced ventricular arrhythmias begin to be significant in the asymptomatic population86,87. d, e Correlation between Kd and age of onset (d) and between koff and age of onset (e) for the variants tested. Reactions were performed as duplicates. Data are presented as mean values and error bars as SD.
