SDS-PAGE analyses of actin and muscle thin filament preparations. (A) Rabbit back muscle actin (#1610374; Colormarker Biorad, Precision Plus Protein Dual Color Standard) and chicken actin preparations (#26614; Thermo Fisher Scientific, PageRuler Unstained Protein Ladder). (B) Ventricular (left) and M. soleus (right) muscle native thin filament composition. Source data are available for this figure: SourceData FS3.