FIGURE 12.

Thermodynamic and structural characterization of the interaction between the Cx32CT CMTX mutants and CaM. NMR spectra and the ITC profile of the CaM/Cx32CT-R219H (A), CaM/Cx32CT-R230C (B), and CaM/Cx32CT-F235C (C) interactions. Top panels, each titration contained the same concentration of ¹⁵N-Cx32CT mutant (100 μm) with different concentrations of CaM. ¹⁵N-HSQC spectrum for each Cx32CT mutant alone (black) has been overlaid with spectra obtained in the presence of different concentrations of CaM (Cx32CT:CaM 1:0 (black), 1:0.25 (red), 1:0.5 (blue), 1:1.5 (green)). Lower panels, the ITC runs were performed at 37 °C. The upper halves show the original heat production upon injection and the lower panels show the integrated, dilution-corrected, and normalized peaks. IB, immunoblot.