Table 2.

Urea denaturation of S2 proteins at 4°C and S2loop proteins at 4°C and 25°C

	S2, 4°C		S2loop
	WT	D187N	4°C			25°C
			WT	D187N	D187Y	WT	D187N
[urea]1/2 (M)	2.25  ± 0.02	2.45  ± 0.03	2.42  ± 0.01	2.33  ± 0.01	1.80  ± 0.01	2.32  ± 0.01	1.79  ± 0.01
m (cal mol−1⋅M−1)	1054  ± 54*	1159  ± 61*	1464  ± 32*	1453  ± 20*	2115  ± 42*	1393  ± 53*	1630  ± 60*
ΔG° (cal mol−1)	2371  ± 118	2839  ± 171	3544  ± 78	3385  ± 48	3807  ± 78	3232  ± 124	2918  ± 109
Δ(ΔG°) (cal mol−1)		−468  ± 207		159  ± 92	−263  ± 110		314  ± 165

^*The calculated m value is 1471 cal mol⁻¹⋅M⁻¹ for S2 and 1635 cal mol⁻¹⋅M⁻¹ for S2loop.