TABLE 1.

Diliganded gating parameters f₂ indicates diliganded opening rate constant; b₂ indicates diliganded closing rate constant; E₂ indicates diliganded gating equilibrium constant (= f₂/b₂); ΔΔG indicates free energy, = 0.59·ln(E₂^WT/E₂^mut). A positive value indicates that the mutation destabilized O relative to C.

Construct	Rate constant		Equilibrium constant
	f2	b2	E2	Fold change	ΔΔG
	s–1					kcal mol–1
WTa	48,000	1700	28.2
εW55A	3860	1970	1.9	14.4	+1.6
εW55E	8670	1960	4.4	6.4	+1.1
εW55F	5440	1200	4.5	6.2	+1.1
εW55I	32,660	1730	18.9	1.5	+0.2
εW55V	5190	3120	1.7	17.0	+1.7
εW55Y	4360	1670	2.6	10.8	+1.4
δW57A	29,510	1720	17.2	1.6	+0.3
δW57E	19,050	810	23.6	1.2	+0.1
δW57F	11,880	1690	7.0	4.0	+0.8
δW57H	14,720	1830	8.0	3.5	+0.7
δW57L	14,000	1990	7.0	4.0	+0.8
δW57R	5490	3280	1.7	16.9	+1.7
δW57V	5670	1980	2.9	9.8	+1.4
δW57Y	26,910	1650	16.3	1.7	+0.3

^aData are from Ref. 39