Table 2.

Thermodynamic parameters for model multimeric proteins as determined by transition midpoint analysis of SUPREX curves (Method 2)

Protein (oligomeric state)	Protein concentration (μM)a	m1b (kcal mol−1 M−1)	m2c (kcal mol−1 M−1)	Literature m (kcal mol−1 M−1)	ΔGf1°d (kcal mol−1)	ΔGf2°e (kcal mol−1)	Literature ΔGf° (kcal mol−1)
GCN4p1 (Dimer)	10	2.0 ± 0.4	1.7	1.9f	−9.4 ± 0.6	−9.2 ± 0.5	−10.5f
	56				−9.2 ± 0.7	−8.8 ± 0.5
ArcR (Dimer)	5	3.8 ± 0.4	2.8	3.6g	−11.4 ± 0.3	−11.0 ± 0.2	−10.6g
	12				−11.1 ± 0.5	−10.6 ± 0.3
	18				−11.8 ± 0.6	−11.1 ± 0.4
	25				−11.5 ± 0.4	−10.9 ± 0.3
	50				−11.6 ± 0.5	−10.8 ± 0.3
					h	h
(DOA20)ArcR (Dimer)	72	2.0 ± 0.4	2.8	3.0i	−8.7 ± 0.2	−8.8 ± 0.3	−8.6i
	72				−8.6 ± 0.4	−8.6 ± 0.6
	72				−9.0 ± 0.2	−9.2 ± 0.3
	190				−7.7 ± 0.2	−7.7 ± 0.3
					h	h
Coil-VaLd (Trimer)	12	2.6 ± 0.6	2.3	2.74j	−18.2 ± 1.3	−17.9 ± 1.0	−18.4j
	28				−18.5 ± 1.5	−18.0 ± 1.1
4-OT (Hexamer)	1.7	11.1 ± 1.8	9.7	11.7k	−66.8 ± 6.6	−63.7 ± 5.1	−61.7k

^a Protein concentrations are expressed as [n-mer]. ^bm₁ = m_app (from Table 1) × # subunits; reported with standard error. ^cm₂ = # residues in n-mer × 0.026 kcal mol⁻¹ M⁻¹ residue⁻¹ (Myers et al. 1995). ^dCalculated using m₁ with equation 8; reported with standard error. ^eCalculated using m₂ with equation 8; reported with standard error assuming a 10% error in m₂. ^fZitzewitz et al. 1995. ^gWales and Fitzgerald 2001. ^hWeighted mean and standard error. ⁱWales and Fitzgerald, unpublished results. ^jBoice et al. 1996. ^kSilinski et al. 2001