Fig. 1. Quantification of troponin exchange in cardiomyocytes by immunoblotting.
A. Immunoblot stained with an antibody against troponin T (cTnT) that recognizes both endogenous cTnT (lower band) and recombinant Myc-tag labeled cTnT (cTnT-myc; upper band). An example is shown of a suspension of IDCM cardiomyocytes exchanged with recombinant cTn containing wild-type cTnI (Wt), pseudo-phosphorylated cTnI at Ser42/44 (42D/44D) or pseudo-dephosphorylated cTnI at Ser42/44 (42A/44A) at 1 mg/mL. B. The average percentages of cTn exchange in cardioymyocytes after overnight incubation in exchange solution with 1 mg/mL cTn containing the different cTnI species (average values represent cTn exchange experiments in cardiomyocytes isolated from 3 IDCM hearts). No significant differences were found in exchange percentage between the three cTnI complexes.