Table 1.

Denaturation parameters for Dns c₅₅₂ variants

	Fluorescence*			Circular dichroism§			Absorption¶
Variant	[Gdn]1/2 (M)	M (kJ/mol/M)	−ΔGw (kJ/mol)	[Gdn]1/2 (M)	M (kJ/mol/M)	−ΔGw (kJ/mol)	[Gdn]1/2 (M)	M (kJ/mol/M)	−ΔGw (kJ/mol)
WT	4.1 ± 0.02†	11.9 ± 0.8†	49 ± 4†	4.1 ± 0.03	13.2 ± 1.6	54 ± 7	4.3 ± 0.02	11.9 ± 0.8	49 ± 4
Dns6	n.d.‡	n.d.‡	n.d.‡	4.0 ± 0.06	9.3 ± 1.8	37 ± 8	4.3 ± 0.02	7.1 ± 0.3	31 ± 1
Dns40	4.3 ± 0.05	9.1 ± 1.2	39 ± 6	4.1 ± 0.04	7.6 ± 0.8	31 ± 4	4.2 ± 0.05	6.4 ± 0.6	27 ± 3
Dns59	4.1 ± 0.05	7.9 ± 1.1	32 ± 5	3.9 ± 0.05	11.1 ± 1.9	43 ± 8	4.3 ± 0.06	5.8 ± 0.5	25 ± 3
Dns76	4.4 ± 0.02	11.0 ± 0.7	48 ± 3	4.3 ± 0.05	11.0 ± 2.0	47 ± 9	4.4 ± 0.03	8.6 ± 0.7	38 ± 3
Dns95	4.2 ± 0.02	12.2 ± 0.9	51 ± 4	4.1 ± 0.04	9.6 ± 1.1	39 ± 5	4.2 ± 0.03	9.7 ± 0.8	41 ± 4
Dns110	4.2 ± 0.02	12.8 ± 1.5	51 ± 6	3.9 ± 0.03	13.2 ± 2.0	51 ± 8	4.1 ± 0.03	7.7 ± 0.6	32 ± 3
Dns126	4.0 ± 0.01	12.0 ± 0.5	48 ± 2	3.9 ± 0.04	10.7 ± 1.5	42 ± 6	4.2 ± 0.03	7.7 ± 0.6	32 ± 3

Measured at 25 °C in pH 3.0 citrate buffer (10 mM for circular dichroism and 100 mM for fluorescence and heme absorption).

*Steady-state measurements of Dns fluorescence intensities. Excitation and emission wavelength are 355 and 513 nm, respectively.

^†Data of WT were taken from Trp91 fluorescence. Excitation and emission wavelength are 290 and 360 nm, respectively.

^‡Not determined (n.d.) because of negligible difference between native and denatured states.

^§Ellipticity measurements at 222 nm.

^¶Heme absorbance measurements at 391 nm.