Table 1.

Binding parameters for medical azoles with CaCYP51, Δ60HsCYP51, and HsCYP51^a

Medical azole antifungal	CaCYP51		Δ60HsCYP51		HsCYP51		Fold difference in Kd
	Kd (nM)	ΔAmax	Kd (nM)	ΔAmax	Kd (nM)	ΔAmax	Δ60HsCYP51/CaCYP51	HsCYP51/CaCYP51
Clotrimazole	26 ± 6	0.0615 ± 0.0015	55 ± 5	0.0964 ± 0.0028	65 ± 19	0.1091 ± 0.0069	2.1	2.5
Fluconazole	56 ± 4	0.0595 ± 0.0016	30,400 ± 4,100	0.0144 ± 0.0006	30,500 ± 7,700	0.0299 ± 0.0047	543	545
Itraconazole	19 ± 5	0.0493 ± 0.0014	92 ± 7	0.0533 ± 0.0048	131 ± 13	0.0707 ± 0.0036	4.8	6.9
Ketoconazole	12 ± 3	0.1073 ± 0.0019	42 ± 16	0.1315 ± 0.0063	61 ± 17	0.1284 ± 0.0081	3.5	5.1
Voriconazole	10 ± 2	0.0590 ± 0.0032	2,290 ± 120	0.0775 ± 0.0021	2,240 ± 520	0.0480 ± 0.0031	229	224

^aCYP51 concentrations of 5 μM were used. A rearrangement of the Morrison equation was used to determine K_d values for the ligands with tight binding (40). Mean K_d and ΔA_max values of three replicates are shown with the associated standard deviations.