. Author manuscript; available in PMC: 2012 Dec 1.

Published in final edited form as: Future Med Chem. 2012 Feb;4(2):227–243. doi: 10.4155/fmc.11.190

Table 3.

Kinetic characteristics of cocaine-metabolizing enzymes with (−)cocaine as substrate.

Enzyme	Catalytic rate constant, k_cat (min⁻¹)	Michaelis constant, K_m (µM)	Catalytic efficiency (k_cat/K_m)	Improvement over wild-type BChE
BChE wild-type	3	4	1.25
BChE double mutant^†	154	18	8.7	~sevenfold
BChE quadruple mutant (AME 359)^‡	620	20	31	~25-fold
BChE sextuple mutant^§	4430	3.5	1300	~1000-fold
TV-1380^¶	2700	2.1	1300	~1000-fold
Bacterial cocaine esterase – wild-type	2323	21	110	~90-fold
Bacterial cocaine esterase – thermostable double mutant^#	2247	24	95	~75-fold

^†

Ala328Trp/Tyr332Ala.

^‡

Phe227Ala/Ser287Gly/Ala328Trp/Tyr332Met.

^§

Ala199Ser/Phe227Ala/Ser287Gly/Ala328Trp/Tyr332Gly/Glu441Asp.

^¶

BChE quadruple mutant (Ala199Ser/Ser287Gly/Ala328Trp/Tyr332Gly) fused with human serum albumin.

Thr172Arg/Gly173Glu.

BChE: Butyrylcholinesterase.

Data from [55,56,61].