FIGURE 4.

Determination of secondary structural characteristics of WT-cTnC by CD in various cation-bound states. The spectra compares the changes in α-helical content of WT-cTnC (−F27W) under different conditions as follows: apo, Mg²⁺-bound, Mg²⁺/Ca²⁺-bound states. Far-UV CD was recorded at 195–250 nm with a bandwidth of 1 nm at a speed of 50 nm/min and a resolution of 0.5 nm at room temperature (20 °C). Mean residue ellipticity ([θ]MRE, in degree·cm²/dmol) for the spectra was calculated utilizing the same Jasco system software and the following equation: [θ]MRE = [θ]/(10 × Cr × l), where [θ] is the measured ellipticity in millidegrees; Cr is the mean residue molar concentration, and l is the path length in centimeters.