Table 5.

Kinetic constants of the recombinant hCE-1 and hCE-2 for various substrates

Substrate	hCE-1			hCE-2			Preference indexa
	Km(μM)	kcat(min-1)	kcat/Km(μM-1 min1)	Km(μM)	kcat(min-1)	kcat/Km(μM-1 min-1)
pNPA	27 ± 1	1020 ± 30	38 ± 1.4	31 ± 2	4200 ± 240	140 ± 8
(αR)(1R)-cis-A3	0.3 ± 0.1	0.19 ± 0.06	0.71 ± 0.29	0.9 ± 0.2	0.11 ± 0.03	0.14 ± 0.04	0.71
(αR)(1R)-trans-A3	1.7 ± 0.5	1.3 ± 0.3	0.74 ± 0.03	2.5 ± 0.1	0.32 ± 0.07	0.13 ± 0.03	0.76
(αR)(1S)-cis-A3	1.5 ± 0.5	0.09 ± 0.03	0.06 ± 0.03	1.7 ± 0.3	0.10 ± 0.02	0.06 ± 0.01	-0.01
(αR)(1S)-trans-A3	1.9 ± 0.8	1.7 ± 0.4	0.87 ± 0.03	1.9 ± 0.7	2.2 ± 0.3	1.2 ± 0.4	-0.14
(αS)(1R)-cis-A3	0.3 ± 0.1	0.19 ± 0.06	0.57 ± 0.03	2.5 ± 0.7	0.28 ± 0.04	0.11 ± 0.03	0.71
(αS)(1R)-trans-A3	0.7 ± 0.4	4.4 ± 0.6	6.6 ± 0.03	2.8 ± 0.1	0.48 ± 0.03	0.17 ± 0.01	1.59
(αS)(1S)-cis-A3	1.4 ± 0.4	0.07 ± 0.02	0.05 ± 0.03	4.0 ± 0.9	0.71 ± 0.21	0.18 ± 0.05	-0.56
(αS)(1S)-trans-A3	2.4 ± 0.8	1.7 ± 0.4	0.71 ± 0.03	3.8 ± 0.4	4.6 ± 0.3	1.2 ± 0.1	-0.23
(2R)(αR)-A4	0.7 ± 0.2	0.10 ± 0.02	0.15 ± 0.03	0.9 ± 0.3	0.51 ± 0.10	0.56 ± 0.16	-0.57
(2R)(αS)-A4	0.8 ± 0.3	0.13 ± 0.02	0.16 ± 0.03	2.0 ± 0.3	3.5 ± 0.7	1.8 ± 0.4	-1.05
(2S)(αR)-A4	—b	—	—	—	—	—
(2S)(αS)-A4	0.8 ± 0.3	0.03 ± 0.01	0.04 ± 0.03	—	—	—
A6	1.8 ± 0.3	0.25 ± 0.06	0.14 ± 0.03	2.1 ± 0.3	0.34 ± 0.05	0.16 ± 0.02
A8	1.5 ± 0.2	0.30 ± 0.05	0.20 ± 0.03	5.4 ± 1.2	0.31 ± 0.05	0.06 ± 0.01
Cypermethrin (B3)	20 ± 2	1.3 ± 0.1	0.07 ± 0.01	9.1 ± 2.0	4.0 ± 0.9	0.44 ± 0.10
4-Methylumbelliferyl acetatec	800		2.0	150		60.0
Cocained	120			390		0.0184
Heroine	6300		0.069	6800		0.314
6-Monoacetylmorphinee	8300		0.000024	130		0.022
Meperidinef	1900		0.00035
CPT-11g	42.7	0.031	0.00073	3.4	0.160	0.047

^aPreference indexD log((catalytic eYciency of hCE-1)/(catalytic eYciency of hCE-2)).

^bHydrolytic activity was not detected.

^cData are from Pindel et al. [38].

^dData for hCE-1 are from Brzezinski et al. [39] and for hCE-2 are from Pindel et al. [38].

^eData are from Kamendulis et al. [40].

^fData are from Zhang et al. [41].

^gData are from Humerickhouse et al. [42].