TABLE 1

Kinetic parameters determined for (−)-cocaine and ACh hydrolyses catalyzed by wild-type BChE and its mutants

Unless indicated otherwise, all kinetic parameters listed in this table were determined in the present study. Relative catalytic efficiency (k_cat/K_M) is the ratio of the k_cat/K_M value of the mutant to that of wild-type BChE against the same substrate.

Substrate and Enzyme	K_M	k_cat	k_cat/K_M	Relative Catalytic Efficiency
	μM	min⁻¹	M⁻¹ min⁻¹
(−)-Cocaine
Wild-type BChE^{^a}	4.5	4.1	9.1 × 10⁵	1
A199S/S287G/A328W/Y332G^{^b}	3.1	3060	9.9 × 10⁸	1080
A199S/F227A/S287G/A328W/E441D	1.1	1730	1.6 × 10⁹	1730
A199S/F227A/S287G/A328W/Y332G/E441D	3.5	4430	1.3 × 10⁹	1390
ACh
Wild-type BChE	148	86,000	5.8 × 10⁸	1
A199S/S287G/A328W/Y332G	36	7500	2.1 × 10⁸	0.36
A199S/F227A/S287G/A328W/E441D	27	14,600	5.4 × 10⁸	0.93
A199S/F227A/S287G/A328W/Y332G/E441D	75	13,800	1.8 × 10⁸	0.32

↵a Data from Sun et al. (2002a).
↵b The kinetic parameters reported in Yang et al. (2010). The experimental measurement in the present study was able to reproduce the kinetic parameters.