Figure 2. Steady state measurements with the RLC AF488-Cy3 ATP FRET sensor reports on structural changes in human β-cardiac 15-hep HMM due to changes in salt (KOAc) concentration.

(A) Fluorescence emission spectra of 15-hep myosin with FRET sensor in the presence of 0 mM salt (blue curve) and 150 mM salt (red curve). (B) FRET efficiency calculated from the fluorescence emission spectra obtained at different salt concentrations is plotted along with the % SRX state obtained from the single-turnover assay.