Salt dependence of the CARDa-CARDb interaction.

ITC measurements were performed at 30°C in 50 mM Tris-HCl, 2 mM DTT, pH 7.5 with the ionic strength ranging from 50–1000 mM NaCl. Sample concentrations were 430–594 µM in the syringe (CARDa) and 38–52 µM in the cell (CARDb). The low n-value (N = 0.6) obtained at 50 mM NaCl may reflect that CARDb is partially unfolded at this NaCl concentration.