FIGURE 8.

Cardiac TnI Ser-150 phosphorylation does not alter cTnI PKA-dependent phosphorylation. Recombinant human cTn containing wild-type or Ser-150 pseudophosphorylated cTnI (Tn S150D) was incubated with the PKA catalytic subunit for varied times before stopping the reaction. A, phosphorylation of cTnI detected by Pro-Q Diamond phosphoprotein-specific stained gels demonstrates the time-dependent increase in cTnI phosphorylation. After Pro-Q Diamond staining, gels were subjected to Sypro Ruby staining to determine total cTnI amount. B, fit of cTnI phosphorylation normalized to total cTnI demonstrates PKA-dependent phosphorylation of Tn S150D (black circle, solid line) over time was not different from that of Tn WT (gray triangle, dashed line). A.U., absorbance units.