Table 2.

Parameters characterizing the urea unfolding of VHP and hydrophobic variants in 50 mM Sodium Phosphate, pH 7.0, 25 °C ^a

Variant	Urea 1/2b (M)	Δ Urea 1/2c (M)	md (cal mol−1M−1)	ΔG (H2O) e (kcal mol−1)	ΔΔG f (kcal mol−1)
WT	6.17	-	450	2.7	-
L2A	3.22	− 2.95	470	1.5	− 1.4
V10A	4.61	− 1.56	460	2.1	− 0.7
F11A	1.30	− 4.87	494	0.6	− 2.3
L29A	2.76	− 3.41	450	1.2	− 1.6
L35A	5.19	− 0.98	470	2.4	− 0.5

^aThe urea denaturation curves were analyzed as described. ⁹⁸

^bMidpoint of the unfolding curve. The error is ± 1%.

^cΔ Urea _1/2 = Urea _1/2 (variant) − Urea _1/2 (WT).

^dThe slope of plots of ΔG versus [Urea]. The error is ± 10%.

^eΔG (H₂O) = the intercept of plots of ΔG versus [Urea] at 0 M Urea.

^fFrom Δ Urea _1/2 × the average m value of WT and the variants (466 cal mol⁻¹M⁻¹).