ΔHcal 108μM protein
Enthalpy of Unfolding (ΔH)
Differential Scanning Calorimetry (DSC)
0.1 M sodium cacodylate–HCl (pH 7.0) and 1.5 M GdmCl
DSC = differential scanning calorimetry
For the wild-type Gβ1 protein and Gβ1-M2, DSC measurements were performed with a VP-DSC instrument (MicroCal, Northampton, MA, USA) at concentrations between 62 and 139 μM in 0.1 M sodium cacodylate–HCl (pH 7.0) and 1.5 M GdmCl at a scan rate of 1.5 K min− 1 (cell volume, 0.523 ml). The measured excess molar heat capacity CEp(T) was analyzed by a nonlinear least-squares method according to a non-two-state model after correction for a progressive baseline (assumption of 0 ΔCp). For the analysis, the Origin software provided by MicroCal was used.