Hydrolyzes cocaine to benzoate and ecgonine methyl ester, endowing the bacteria with the ability to utilize cocaine as a sole source of carbon and energy for growth, as this bacterium lives in the rhizosphere of coca plants. Also efficiently hydrolyzes cocaethylene, a more potent cocaine metabolite that has been observed in patients who concurrently abuse cocaine and alcohol. Is able to prevent cocaine-induced convulsions and lethality in rat. cocaine + H2O = benzoate + ecgonine methyl ester + H(+) kcat is 7.8 sec(-1) with cocaine as substrate, and 9.4 sec(-1) with cocaethylene. Optimum pH is 9.0. Is relatively unstable at physiological temperatures since it displays a half-life of 13 minutes in rat plasma at 37 degrees Celsius. Alkaloid degradation; cocaine degradation. Homodimer. The protein aggregates upon heat inactivation. Positively induced by cocaine. It consists of three domains: domain 1 contains the active site; domains 2 and 3 are involved in substrate recognition. Domain 1 contains the GxSxxG motif found in most members of the alpha/beta hydrolase superfamily. Because of the high catalytic proficiency of CocE, it is an attractive candidate for novel protein-based therapies for cocaine overdose, as this cocaine-degrading enzyme could be used for rapid cocaine detoxification in an emergency setting. However, wild-type CocE is relatively unstable, but this can be improved by specific mutations. Thus, improved stability of engineered CocE enzymes will have a profound influence on the use of this protein to combat cocaine-induced toxicity and addiction in humans. Has also a potential as a highly-sensitive drug detector. This enzyme hydrolyzes cocaine faster than any other known cocaine esterase. Incorporating disulfide bonds between cysteine residues substituted at Gly-4 and Ser-10 conveys significant improvements to the thermostability and the half-life at 37 degrees Celsius. Moreover, in combination with T172R/G173Q mutations, the disulfide-stabilized dimer (CCRQ-CocE) remains more than 90% active for longer than 40 days at 37 degrees Celsius, representing a >4700-fold improvement over wt-CocE. The enhanced stability serves as a better substrate for modification, with polyethylene glycol (PEG) moieties providing the therapeutic with stealth properties. PEGylated CCRQ-CocE retains full in vitro enzymatic activity, protects rodents up to 72 hours in a cocaine overdose model, diminishes self-administration for 72 hours in rats, reduces cocaine-induced cardiovascular effects and locomotor functions in monkeys for up to 48 hours, and displays reduced immunogenicity in mice. Belongs to the CocE/NonD hydrolase family. Rhodococcus: Nature's junkie - Issue 27 of October 2002