Table 4. Parameters for urea denaturation of wild-type and mutant forms (I154F and W155R) to compare the differences in stability.

Δ[Urea]_1/2=difference between the [urea]_1/2 for the wild-type and the mutant forms. ΔΔG=from Δ[urea]_1/2×average of the three m values [18].

Protein	ΔGH2O (kJ·mol−1)	m (J·mol−1·M−1)	[Urea]1/2 (M)	Δ[Urea]1/2	ΔΔG (J·mol−1)	Tm (°C)	ΔTm (°C)
Wild-type	24.3±1.3	5665±264	4.3			66.3±0.1
W155R	21.4±0.8	6209±327	3.4	−0.9	−7172	61.4±0.4	−4.9
I154F	24.7±0.8	7687±281	3.2	−1.1	−5866	50.7±0.1	−15.6