FIGURE 4.

Representative tension trace (at pCa 5.4) for isolated rat LV cardiac myofibril after exchanging with recombinant cTn complexes containing cTnI^WT, cTnI^R146G, and cTnI^R21C. The inset is a close-up of slow phase of relaxation demonstrating how k_{rel, slow} and t_{rel, slow} are measured.