Download MendeleyRational design, preparation, and characterization of a therapeutic enzyme mutant with improved stability and function for cocaine detoxification.
Fang, L., Chow, K.M., Hou, S., Xue, L., Chen, X., Rodgers, D.W., Zheng, F., Zhan, C.G.(2014) ACS Chem Biol 9: 1764-1772
- PubMed: 24919140
- DOI: https://doi.org/10.1021/cb500257s
- Primary Citation of Related Structures:
4P08 - PubMed Abstract:
Cocaine esterase (CocE) is known as the most efficient natural enzyme for cocaine hydrolysis. The major obstacle to the clinical application of wild-type CocE is the thermoinstability with a half-life of only ∼12 min at 37 °C. The previously designed T172R/G173Q mutant (denoted as enzyme E172-173) with an improved in vitro half-life of ∼6 h at 37 °C is currently in clinical trial Phase II for cocaine overdose treatment. Through molecular modeling and dynamics simulation, we designed and characterized a promising new mutant of E172-173 with extra L196C/I301C mutations (denoted as enzyme E196-301) to produce cross-subunit disulfide bonds that stabilize the dimer structure. The cross-subunit disulfide bonds were confirmed by X-ray diffraction. The designed L196C/I301C mutations have not only considerably extended the in vitro half-life at 37 °C to >100 days, but also significantly improved the catalytic efficiency against cocaine by ∼150%. In addition, the thermostable E196-301 can be PEGylated to significantly prolong the residence time in mice. The PEGylated E196-301 can fully protect mice from a lethal dose of cocaine (180 mg/kg, LD100) for at least 3 days, with an average protection time of ∼94h. This is the longest in vivo protection of mice from the lethal dose of cocaine demonstrated within all studies using an exogenous enzyme reported so far. Hence, E196-301 may be developed to become a more valuable therapeutic enzyme for cocaine abuse treatment, and it demonstrates that a general design strategy and protocol to simultaneously improve both the stability and function are feasible for rational protein drug design.
Organizational Affiliation:
Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , 789 South Limestone Street, Lexington, Kentucky 40536, United States.
