Table 2.

Thermodynamic linkage between NaCl binding and protomer self-assembly

Fitting Parameters	Best Fit Values
	m = 3 (Fixed)	m = 4 (Fixed)
K1	K1 = 2.6 × 1013 M−3	K1 = 9.1 × 1016 M−3
(K1)1/3 = 3.0 × 104 M−1	(K1)1/3 = 4.5 × 105 M−1
K2	K2 = 3.2 × 1012 M−12	K2 = 8.8 × 109 M−16
(K2)1/12 = 11.0 M−1	(K2)1/16 = 4.2 M−1
K3	K3 = 2.2 × 105 M−12	K3 = 2.2 × 106 M−16
(K3)1/12 = 2.8 M−1	(K3)1/16 = 3.4 M−1
K4a	K4 = 3.8 × 1020 M−3	K4 = 3.6 × 1020 M−3
(K4)1/3 = 7.2 × 106 M−1	(K4)1/3 = 7.1 × 106 M−1

The data presented in Fig. 5B were analyzed according to the thermodynamic linkage model presented in Fig. 5C. The number of ions involved, m, was fixed at either 3 or 4, as indicated, while the microscopic equilibrium constants K₁, K₂, and K₃ were allowed to float in the NLLS analysis. (Solid blue and green lines) Best fits of the data, respectively, are presented in Fig. 5B.

^aK₄ was calculated from K₁, K₂, and K₃ based on the model presented in Fig. 5C.