A Cocaine Hydrolase Engineered from Human Butyrylcholinesterase Selectively Blocks Cocaine Toxicity and Reinstatement of Drug Seeking in Rats

Abstract

Successive rational mutations of human butyrylcholinesterase (BChE) followed by fusion to human serum albumin have yielded an efficient hydrolase that offers realistic options for therapy of cocaine overdose and abuse. This albumin-BChE prevented seizures in rats given a normally lethal cocaine injection (100 mg/kg, i.p.), lowered brain cocaine levels even when administered after the drug, and provided rescue after convulsions commenced. Moreover, it selectively blocked cocaine-induced reinstatement of drug seeking in rats that had previously self-administered cocaine. The enzyme treatment was well tolerated and may be worth exploring for clinical application in humans.

Long-Term Reduction of Cocaine Self-Administration in Rats Treated with Adenoviral Vector-Delivered Cocaine Hydrolase: Evidence for Enzymatic Activity

“…Brain samples were homogenized in 10 mM sodium phosphate pH 7.5 with 0.1% Tween 80 and DFP (10 À 5 M), mixed well, and centrifuged for 5 min at 2500 g to obtain supernatant for assay. For determinations of radiolabeled cocaine, 200 ml of plasma or 200 ml of brain supernatant were then mixed with 1 M Na 2 CO 3 and 4 ml of toluene fluor as previously described by Brimijoin et al (2008).…”

“…with a purified version of CocH protein, an hour before i.p. priming with cocaine, failed to reinstate their drug-seeking behavior (Brimijoin et al, 2008). Delivery of CocH by viral gene transfer increased cocaine metabolism several thousand-fold in rats and mice , Gao and Brimijoin 2004, 2006, and animals showed no locomotor response to normal stimulatory doses of cocaine (Carroll et al, 2012).…”

Long-Lasting Effects of a PEGylated Mutant Cocaine Esterase (CocE) on the Reinforcing and Discriminative Stimulus Effects of Cocaine in Rats

“…In an attempt to improve upon BChE's catalytic efficiency, Zhan and colleagues have used site-directed mutagenesis to create mutant BChEs capable of hydrolyzing cocaine B450-2000 times more efficiently than native BChE (Pan et al, 2005;Zheng et al, 2008). These mutant BChEs have shown promising results when evaluated in rodents, effectively reducing the cardiovascular, lethal, and response-reinstating effects of cocaine (Brimijoin et al, 2008;Xue et al, 2010;Zheng et al, 2008). In addition, an albumin-fused mutant BChE (Albu-CocH) has been shown to decrease progressive ratio responding for cocaine (Carroll et al, 2011), suggesting that it is also capable of reducing the reinforcing effectiveness of cocaine.…”

Avances en el desarrollo de productos biológicos para el tratamiento de la adicción a las drogas y las sobredosis

“…That way, in the case of cocaine dependence, a treatment with e-BChE may prevent the access of cocaine to the brain and eventually extinguish the brain reward mechanisms associated with the addiction. In the case of overdose, the administration of e-BChE, if it is soon enough, may prevent the central nervous system complications associated with coca ine overdose (Brimijoin et al, 2008;Zheng et al, 2008).…”

“…A vaccine may not be helpful because of the delay by the immune system to produce levels of antibody titers capable enough to antagonize the drug of abuse and the monoclonal antibody may not be helpful because it would be saturated by the drug of abuse. In both cases, a large proportion of the illicit drug molecules may still be free to access the central nervous syst em (Brimijoin et al, 2008;Gao, Orson, Kinsey, Kosten, & Brimijoin, 2010 Recent advances in the development of biologics, including gene therapy, bioengineer, and nanotechnology methods are providing a wealth of opportunities to discover and develop new biologics that are more potent and specific and with longer duration of action against drugs of abuse. The purpose of this article is to provide a general overview of the research of biologics, specifically vaccines, monoclonal antibodies, and enzymes for the treatment of addiction disorders as well as drug overdose.…”