Table 1.

Kinetic and thermodynamic parameters

Protein	logkfH2O*	logkuH2 O*	mf*	mu*	mU/F†	MPeq†, M	ΔG‡, kcal/mol
SOD1pWTapo	−1.12 ± 0.1	−3.9 ± 0.05	−1.07 ± 0.1	0.46 ± 0.01	1.17 ± 0.10	2.12 ± 0.06	3.6 ± 0.2
SOD1mutapo	−1.25 ± 0.05	−4.41 ± 0.08	−0.96 ± 0.04	0.48 ± 0.01	1.13 ± 0.09	2.54 ± 0.04	4.1 ± 0.2
SOD1mutZn	0.76 ± 0.02	−4.7 ± 0.12	−0.81 ± 0.01	0.22 ± 0.01	0.84 ± 0.05	5.85 ± 0.05	7.2 ± 0.2

*Derived from kinetic data by Eq. 2. The rate constants for SOD1_pWT^apo are slightly different from those published in refs. 5 and 14, which are measured at higher ionic strength. m_f of the apo species are slightly overestimated due to a upward kink of logk_f at low [urea]. The effect seems due to shifts of the folding reaction to parallel pathways and is unlikely to affect the conclusions of the current study.

^†Derived from equilibrium data by Eq 1.

^‡Average of ΔG^kin = −2.3RT(logk_u^{H₂ O} − logk_f^{H₂ O}) and ΔG^eq = − 2.3RT(m_U/FxMP^eq).