Table 1.

Equilibrium dissociation constants for ligand complexes of CcP, CcP(H52L) and metMb at pH 7 ^a

Enzyme	phase	$K_D^{\mathit{app}}$ (M) Imidazole	$K_D^{\mathit{app}}$ (M) 1-Methylimidazole	$K_D^{\mathit{app}}$ (M) 4-Nitroimidazole
yCcP		3.3 ± 0.4	0.85 ± 0.11	~0.2
rCcP		4.6 ± 0.8	0.63 ± 0.04	~0.1
CcP(H52L)	high	0.13 ± 0.04 (<46%)	1.1 ± 0.2	~0.03
	low	9.5 ± 4.5 (>54%)
metMb b		(2.8 ± 0.7) × 10−2	(8.7 ± 1.0) × 10−2	(2.5 ± 0.7) × 10−3

^aThis work - pH 7.0, 1.0 M ionic strength potassium phosphate buffer

^breferences [6, 7].