Cocaine metabolism accelerated by a re-engineered human butyrylcholinesterase.
Plasma butyrylcholinesterase (BChE) is important in the metabolism of cocaine, but natural human BChE has limited therapeutic potential for detoxication because of low catalytic efficiency with cocaine. Here we report pharmacokinetics of cocaine in rats treated with A328W/Y332A BChE, an excellent cocaine hydrolase designed with the aid of molecular modeling. Compared with wild-type BChE, this enzyme hydrolyzes cocaine with 40-fold improved k(cat) (154 min(-1) versus 4.1 min(-1)) and only slightly increased K(M) (18 microM versus 4.5 microM). In rats given this hydrolase (3 mg/kg i.v.) 10 min before cocaine challenge (6.8 mg/kg i.v.), cocaine half-life was reduced from 52 min to 18 min. Mirroring the reductions of plasma cocaine were large increases in benzoic acid, a product of BChE-mediated cocaine hydrolysis. All other pharmacokinetic parameters confirmed a large, dose-dependent acceleration of cocaine removal by the injected cocaine hydrolase. These results show that A328W/Y332A, an efficient cocaine hydrolase in vivo as well as in vitro, might promote cocaine detoxication in a clinical setting.
Sun
Hong
H
Molecular Neuroscience Program, Mayo Foundation for Medical Education and Research, 200 First Street Southwest, Rochester, MN 55905, USA.
Shen
Maryann L
ML
Pang
Yuan-Ping
YP
Lockridge
Oksana
O
Brimijoin
Stephen
S
D019943:Amino Acid Substitution; D002091:Butyrylcholinesterase / Q000378:metabolism*; D003042:Cocaine / Q000097:blood / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D013058:Mass Spectrometry; D008657:Metabolic Clearance Rate; D016296:Mutagenesis; D021122:Protein Subunits; D011994:Recombinant Proteins / Q000378:metabolism; D014018:Tissue Distribution
D021122:Protein Subunits; D011994:Recombinant Proteins; D002091:Butyrylcholinesterase; D003042:Cocaine