Table 1.

Thermodynamic parameters for the unfolding of WT HP36 and the mutants

ProteinTm, °CΔH°(Tm), kcal⋅mol−1ΔG°, kcal⋅mol−1m-valueCM*, M
WT HP3673.0 ± 0.231.82 ± 0.333.17 ± 0.060.52 ± 0.016.2
K48M78.0 ± 0.434.07 ± 0.384.11 ± 0.080.52 ± 0.017.9
K65M77.2 ± 0.633.20 ± 0.653.87 ± 0.080.52 ± 0.017.2
K70M82.2 ± 0.733.44 ± 0.444.37 ± 0.080.52 ± 0.018.4
  • Experiments were conducted in 10 mM sodium acetate, 150 mM sodium chloride at pH 5.0. SEs of the fit are provided as measures of parameter uncertainty.

  • * The CM value was determined by calculating the derivative of the plot of CD signal vs. [urea].

  • The ΔG° values are calculated using the following: ΔG° = CM × m value.

  • The high thermal stability of the variants prevents an accurate determination of the m-value (given in kilocalories per mole-molarity), so the value of WT HP36 is used.