Table 2. Kinetic parameters for the unfolding of wild type and mutants of TAPLRR.

$\ln k_{\mathrm{u}}^{{\mathrm{H}}_2\mathrm{O}}$ and $m_{\mathrm{u}}^{{\mathrm{H}}_2\mathrm{O}}$ were obtained by fitting the unfolding data to a quadratic equation. To minimise the errors, a weighted-average value of the curvature was calculated using the wild type and mutants (<m*> = −0.052). The data were then refitted to a quadratic equation with m* fixed to the weighted-averaged value. The data were also fitted to give the rate constants for unfolding at 5.5 M urea, in the middle of the denaturant concentration range used for the unfolding kinetics, in order to avoid the need for large extrapolation back to 0 M urea and thereby reduce the errors. The errors listed are the standard deviations from the fits of the data. The Φ values were calculated at 5.5 M urea and they have errors of 5-10%.

	$\ln k_{\mathrm{u}}^{{\mathrm{H}}_2\mathrm{O}}$	mu (M−1)	$\ln k_{\mathrm{u}}^{5.5M}$	Φ 5.5M
WT	−4.18 ± 0.03	1.09 ± 0.01	0.26 ± 0.01
L212V	−2.74 ± 0.12	0.99 ± 0.02	1.13 ± 0.03	0.63 ± 0.13
L238I	−2.08 ± 0.12	1.02 ± 0.02	1.93 ± 0.03	< 0
I264V	−2.48 ± 0.07	0.99 ± 0.01	1.39 ± 0.02	−0.05 ± 0.17
L267I	−4.07 ± 0.09	0.95 ± 0.02	−0.42 ± 0.03	> 1
L293I	−3.65 ± 0.11	1.01 ± 0.02	0.33 ± 0.03	0.95 ± 0.04
L293V	−4.18 ± 0.10	1.05 ± 0.02	0.01 ± 0.03	1.11 ± 0.03
L315A	−2.74 ± 0.09	1.05 ± 0.02	1.47 ± 0.02	0.57 ± 0.07
L317I	−2.57 ± 0.93	0.94 ± 0.02	1.04 ± 0.03	0.46 ± 0.09
L348I	−4.04 ± 0.06	1.07 ± 0.01	0.29 ± 0.02	0.97 ± 0.04