Table 4. Thermodynamic parameters of binding of different inhibitors to B. anthracis lumazine synthase.

1 kcal = 4.186 kJ.

	BaLS–TS23	BaLS–JC72	BaLS–JC33	MtLS–JC33 (Morgunova et al., 2006 ▶)	CaLS–JC33 (Morgunova et al., 2007 ▶)
No. of sites n	0.97 ± 0.06	0.98 ± 0.12	0.98 ± 0.04	0.98 ± 0.04	1.15 ± 0.03
Dissociation constant Kd (µM)	2.02 ± 0.03	3.94 ± 0.01	1.75 ± 0.04	0.72 ± 0.02	0.15 ± 0.04
Binding enthalpy ΔH (kcal mol−1)	−3.70 ± 0.27	−5.29 ± 0.8	−7.50 ± 0.07	−10.52 ± 0.11	−6.98 ± 0.24
TΔS† (kcal mol−1)	4.19 ± 0.27	2.20 ± 0.79	0.47 ± 0.07	−2.00 ± 0.12	2.44 ± 0.25
Free energy of binding ΔG† (kcal mol−1)	−7.89 ± 0.01	−7.49 ± 0.01	−7.98 ± 0.02	−8.52 ± 0.05	−9.38 ± 0.01

^†The entropy of the binding reactions (ΔS) and the free-energy change (ΔG) are obtained from the relation ΔG = −RTln(K _a) = ΔH − TΔS; the estimated errors of TΔS and ΔG are obtained from the relations σ_ΔG = and Tσ_ΔS = {[(dΔS/dΔG)σ_ΔG]² + [(dΔS/dΔH)σ_ΔH]²}^1/2 = [(σ_ΔG)² + (σ_ΔH)²]^1/2, respectively (Taylor, 1997 ▶).