title: Effects of a cocaine hydrolase engineered from human butyrylcholinesterase on metabolic profile of cocaine in rats.
abstract: Accelerating cocaine metabolism through enzymatic hydrolysis at cocaine benzoyl ester is recognized as a promising therapeutic approach for cocaine abuse treatment. Our more recently designed A199S/F227A/S287G/A328W/Y332G mutant of human BChE, denoted as cocaine hydrolase-3 (CocH3), has a considerably improved catalytic efficiency against cocaine and has been proven active in blocking cocaine-induced toxicity and physiological effects. In the present study, we have further characterized the effects of CocH3 on the detailed metabolic profile of cocaine in rats administrated intravenously (IV) with 5 mg/kg cocaine, demonstrating that IV administration of 0.15 mg/kg CocH3 dramatically changed the metabolic profile of cocaine. Without CocH3 administration, the dominant cocaine-metabolizing pathway in rats was cocaine methyl ester hydrolysis to benzoylecgonine (BZE). With the CocH3 administration, the dominant cocaine-metabolizing pathway in rats became cocaine benzoyl ester hydrolysis to ecgonine methyl ester (EME), and the other two metabolic pathways (i.e. cocaine methyl ester hydrolysis to BZE and cocaine oxidation to norcocaine) became insignificant. The CocH3-catalyzed cocaine benzoyl ester hydrolysis to EME was so efficient such that the measured maximum blood cocaine concentration (∼38 ng/ml) was significantly lower than the threshold blood cocaine concentration (∼72 ng/ml) required to produce any measurable physiological effects.
authors.affiliation: Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States.
authors.forename: Xiabin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States.
authors.forename: Xirong
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States.
authors.forename: Ziyuan
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States. Electronic address: zhan@uky.edu.
authors.forename: Chang-Guo
authors.initials: CG
authors.lastname: Zhan
authors.affiliation: Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States. Electronic address: fzhen2@email.uky.edu.
authors.forename: Fang
authors.initials: F
authors.lastname: Zheng
mesh_terms: D000818:Animals; D055162:Biocatalysis; D002091:Butyrylcholinesterase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003042:Cocaine / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006867:Hydrolases / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D015202:Protein Engineering; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D011994:Recombinant Proteins; D006867:Hydrolases; D002091:Butyrylcholinesterase; D003042:Cocaine
keywords: Cocaine hydrolase; Drug abuse; Drug metabolism; Enzyme; Metabolite