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Shang L, Wei H, Deng J, Stewart MJ, LeSaint JE, Kyomuhangi A, Park S, Maul EC, Zhan CG, Zheng F. In vitro and in vivo stability of a highly efficient long-acting cocaine hydrolase. Sci Rep 2024; 14:10952. [PMID: 38740850 PMCID: PMC11091111 DOI: 10.1038/s41598-024-61646-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 05/08/2024] [Indexed: 05/16/2024] Open
Abstract
It is recognized as a promising therapeutic strategy for cocaine use disorder to develop an efficient enzyme which can rapidly convert cocaine to physiologically inactive metabolites. We have designed and discovered a series of highly efficient cocaine hydrolases, including CocH5-Fc(M6) which is the currently known as the most efficient cocaine hydrolase with both the highest catalytic activity against (-)-cocaine and the longest biological half-life in rats. In the present study, we characterized the time courses of protein appearance, pH, structural integrity, and catalytic activity against cocaine in vitro and in vivo of a CocH5-Fc(M6) bulk drug substance produced in a bioreactor for its in vitro and in vivo stability after long-time storage under various temperatures (- 80, - 20, 4, 25, or 37 °C). Specifically, all the tested properties of the CocH5-Fc(M6) protein did not significantly change after the protein was stored at any of four temperatures including - 80, - 20, 4, and 25 °C for ~ 18 months. In comparison, at 37 °C, the protein was less stable, with a half-life of ~ 82 days for cocaine hydrolysis activity. Additionally, the in vivo studies further confirmed the linear elimination PK profile of CocH5-Fc(M6) with an elimination half-life of ~ 9 days. All the in vitro and in vivo data on the efficacy and stability of CocH5-Fc(M6) have consistently demonstrated that CocH5-Fc(M6) has the desired in vitro and in vivo stability as a promising therapeutic candidate for treatment of cocaine use disorder.
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Affiliation(s)
- Linyue Shang
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Huimei Wei
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Jing Deng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Madeline J Stewart
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Johnathan E LeSaint
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Annet Kyomuhangi
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Shawn Park
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Elise C Maul
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536, USA.
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2
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Catalytic activities of a highly efficient cocaine hydrolase for hydrolysis of biologically active cocaine metabolites norcocaine and benzoylecgonine. Sci Rep 2023; 13:640. [PMID: 36635293 PMCID: PMC9837138 DOI: 10.1038/s41598-022-27280-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023] Open
Abstract
Cocaine is a widely abused, hepatotoxic drug without an FDA-approved pharmacotherapy specific for cocaine addiction or overdose. It is recognized as a promising therapeutic strategy to accelerate cocaine metabolism which can convert cocaine to pharmacologically inactive metabolite(s) using an efficient cocaine-metabolizing enzyme. Our previous studies have successfully designed and discovered a highly efficient cocaine hydrolase, denoted as CocH5-Fc(M6), capable of rapidly hydrolyzing cocaine at the benzoyl ester moiety. In the present study, we determined the kinetic parameters of CocH5-Fc(M6) against norcocaine (kcat = 9,210 min-1, KM = 20.9 μM, and kcat/KM = 1.87 × 105 min-1 M-1) and benzoylecgonine (kcat = 158 min-1, KM = 286 μM, and kcat/KM = 5.5 × 105 min-1 M-1) for the first time. Further in vivo studies have demonstrated that CocH5-Fc(M6) can effectively accelerate clearance of not only cocaine, but also norcocaine (known as a cocaine metabolite which is more toxic than cocaine itself) and benzoylecgonine (known as an unfavorable long-lasting metabolite with some long-term toxicity concerns) in rats. Due to the desired high catalytic activity against norcocaine, CocH5-Fc(M6) is capable of quickly detoxifying both cocaine and its more toxic metabolite norcocaine after intraperitoneally administering lethal dose of 60 or 180 mg/kg cocaine. In addition, the ability of CocH5-Fc(M6) to accelerate clearance of benzoylecgonine should also be valuable for the use of CocH5-Fc(M6) in treatment of cocaine use disorder.
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Zheng F, Jin Z, Deng J, Chen X, Zheng X, Wang G, Kim K, Shang L, Zhou Z, Zhan CG. Development of a Highly Efficient Long-Acting Cocaine Hydrolase Entity to Accelerate Cocaine Metabolism. Bioconjug Chem 2022; 33:1340-1349. [PMID: 35767675 DOI: 10.1021/acs.bioconjchem.2c00210] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is particularly challenging to develop a truly effective pharmacotherapy for cocaine use disorder (CUD) treatment. Accelerating cocaine metabolism via hydrolysis at cocaine benzoyl ester using an efficient cocaine hydrolase (CocH) is known as a promising pharmacotherapeutic approach to CUD treatment. Preclinical and clinical studies on our first CocH (CocH1), in its human serum albumin-fused form known as TV-1380, have demonstrated the promise of a general concept of CocH-based pharmacotherapy for CUD treatment. However, the biological half-life of TV-1380 (t1/2 = 8 h in rats, associated with t1/2 = 43-77 h in humans) is not long enough for practical treatment of cocaine dependence, which requires enzyme injection for no more than once weekly. Through protein fusion of a human butyrylcholinesterase mutant (denoted as CocH5) with a mutant (denoted as Fc(M6)) of Fc from human IgG1, we have designed, prepared, and tested a new fusion protein (denoted as CocH5-Fc(M6)) for its pharmacokinetic profile and in vivo catalytic activity against (-)-cocaine. CocH5-Fc(M6) represents the currently most efficient long-acting cocaine hydrolase with both the highest catalytic activity against (-)-cocaine and the longest elimination half-life (t1/2 = 229 ± 5 h) in rats. As a result, even at a single modest dose of 3 mg/kg, CocH5-Fc(M6) can significantly and effectively accelerate the metabolism of cocaine in rats for at least 60 days. In addition, ∼70 nM CocH5-Fc(M6) in plasma was able to completely block the toxicity and physiological effects induced by intraperitoneal injection of a lethal dose of cocaine (60 mg/kg).
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Zhao L, Chen J, Tian L, Zhang Y, Chen L, Du X, Ma M, Li J, Meng Q, Li C. Supramolecular Detoxification of Macromolecular Biotoxin through the Complexation by a Large-Sized Macrocycle. Adv Healthc Mater 2022; 11:e2200270. [PMID: 35543330 DOI: 10.1002/adhm.202200270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/19/2022] [Indexed: 11/10/2022]
Abstract
Biotoxins are diverse, complex, and hypertoxic, ultimately serving as grave and lasting menaces to humanity. Here, it is aimed to introduce a new detoxification methodology for macromolecular biotoxin through complexation by a very large macrocycle. A 25-mer peptide isolated from Lycosa erythrognatha spider venom (LyeTxI) is selected as the model macromolecular biotoxin. Quaterphen[4]arene, with a side length of ≈1.6 nm, has a sufficient cavity to bind LyeTxI. Hence, the water-soluble derivative of Quaterphen[4]arene (H) is designed and synthesized. H exhibits an overall host-guest complexation toward LyeTxI, resulting in a considerably high association constant of (7.01 ± 0.18) × 107 m-1 . This encapsulation of peptide is interesting as traditional macrocycles can only engulf the amino acid residues of peptides due to their limited cavity size. In vitro assay verifies that complexation by H inhibits the interactions of LyeTxI with cell membranes, thereby reducing its cytotoxicity, suppressing hemolysis, and decreasing the release of lactate dehydrogenase. Notably, the intravenous administration of H has a significant therapeutic effect on LyeTxI-poisoned mice, alleviating inflammation and tissue damage, and markedly improving the survival rate from 10% to 80%. An efficient and potentially versatile approach is provided to detoxify macromolecular biotoxins, with giant macrocycle serving as an antidote.
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Affiliation(s)
- Liang Zhao
- Center for Supramolecular Chemistry and Catalysis Department of Chemistry Shanghai University Shanghai 200444 P. R. China
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Junyi Chen
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
- Key Laboratory of Inorganic‐Organic Hybrid Functional Material Chemistry Ministry of Education Tianjin Key Laboratory of Structure and Performance for Functional Molecules College of Chemistry Tianjin Normal University Tianjin 300387 P. R. China
| | - Long Tian
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Yahan Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Longming Chen
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Xinbei Du
- Center for Supramolecular Chemistry and Catalysis Department of Chemistry Shanghai University Shanghai 200444 P. R. China
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Mengke Ma
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Jian Li
- Center for Supramolecular Chemistry and Catalysis Department of Chemistry Shanghai University Shanghai 200444 P. R. China
- School of Chemistry and Chemical Engineering Henan Normal University Xinxiang Henan 453007 P. R. China
| | - Qingbin Meng
- State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institute of Pharmacology and Toxicology Beijing 100850 P. R. China
| | - Chunju Li
- Key Laboratory of Inorganic‐Organic Hybrid Functional Material Chemistry Ministry of Education Tianjin Key Laboratory of Structure and Performance for Functional Molecules College of Chemistry Tianjin Normal University Tianjin 300387 P. R. China
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Clinical potential of a rationally engineered enzyme for treatment of cocaine dependence: Long-lasting blocking of the psychostimulant, discriminative stimulus, and reinforcing effects of cocaine. Neuropharmacology 2020; 176:108251. [PMID: 32710979 DOI: 10.1016/j.neuropharm.2020.108251] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 02/06/2023]
Abstract
It is a grand challenge to develop a truly effective treatment of substance use disorder (SUD), particularly for cocaine and other drugs without an FDA-approved treatment available, because a truly effective therapy must effectively block the drug's physiological and reinforcing effects during the entire period of treatment in order to achieve the long-time abstinence required by the FDA. Whether a biologic, such as monoclonal antibody, vaccine, or therapeutic enzyme, can be truly effective for SUD treatment or not has been the subject of extensive debate. The main debate question is whether a biologic, particularly an exogenous enzyme, can effectively block the drug's reinforcing effect. In this report, we demonstrate that a modest dose of a recently redesigned long-acting cocaine hydrolase, CocH3-Fc(M6), can be used to effectively block the psychostimulant, discriminative stimulus, and reinforcing effects of cocaine for a sufficiently long period of time. For example, a dose of 3 mg/kg CocH3-Fc(M6) completely blocked the discriminative stimulus and reinforcing effects for 24/25 days and continued to significantly attenuate/decrease the cocaine effects for at least 29 days in rats. All the animal data consistently suggest that the long-acting cocaine hydrolase is a truly promising candidate of enzyme therapy for treatment of cocaine use disorder.
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Sepehr A, Taheri F, Heidarian S, Motaghinejad M, Safari S. Neuroprotective and neuro-survival properties of safinamide against methamphetamine-induced neurodegeneration: Hypothetic possible role of BDNF/TrkB/PGC-1α signaling pathway and mitochondrial uncoupling protein -2(UCP-2). Med Hypotheses 2020; 143:110094. [PMID: 32682215 DOI: 10.1016/j.mehy.2020.110094] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 06/19/2020] [Accepted: 07/07/2020] [Indexed: 12/16/2022]
Abstract
Methamphetamine is a behavioral psychostimulant that has a high potential for misuse and induction of neurotoxicity. Safinamide is a novel inhibitor of monoamine oxidase B (MAOB) with neuroprotective properties. Methamphetamine abuse causes dysfunction in the respiratory chain of the mitochondria, but the specific signaling mechanism and role of the uncoupling protein-2(UCP-2) remain unclear. As we know, some indirect evidence indicates that neurodegeneration can be caused by inhibition of the brain-derived neurotrophic factor (BDNF) receptor, TrkB and its downstream signaling pathway, such as the PGC-1α protein. Neuroprotective strategies and approaches to the management, treatment or prevention of methamphetamine-induced neurodegeneration by modulating BDNF / TrkB / PGC-1α-UCP-2 can be considered as novel therapeutic approaches to these psychostimulant neurochemical and neurobehavioral approaches. Previous studies have shown that safinamide, a monoamine oxidase-B (MAOB) inhibitor, can function as a neuroprotective agent and inhibit the neurodegenerative process especially in Parkinson's disease but its impact on other neurodegenerative processes and drug-induced neurotoxicity remain unclear. Although there is some evidence that BDNF / TrkB / PGC-1α-UCP-2 signaling pathway and mitochondrial UCP-2 mediated safinamide induced neuroprotection but it's exact and precise mechanism of action and neuroprotective effects in neurodegenerative disorder and the protective properties against methamphetamine induced neurodegeneration and the role of BDNF / TrkB / PGC-1α signaling pathway and role of mitochondrial UCP-2 in this process have not yet been clarified. Therefore, in subjects addicted to methamphetamine, we hypothesized that safinamide will provide neuroprotection against methamphetamine-prompted neurodegeneration, and it appears that BDNF / TrkB / PGC-1α signaling pathway and mitochondrial UCP-2 are likely to play a critical role.
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Affiliation(s)
- Afrah Sepehr
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Fereshteh Taheri
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sara Heidarian
- Department of chemistry, Zagros Institute of Higher Education, Kermanshah, Iran
| | - Majid Motaghinejad
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Sepideh Safari
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
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Zheng F, Chen X, Kim K, Zhang T, Huang H, Zhou S, Zhang J, Jin Z, Zhan CG. Structure-Based Design and Discovery of a Long-Acting Cocaine Hydrolase Mutant with Improved Binding Affinity to Neonatal Fc Receptor for Treatment of Cocaine Abuse. AAPS JOURNAL 2020; 22:62. [PMID: 32189158 DOI: 10.1208/s12248-020-00442-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/28/2020] [Indexed: 01/06/2023]
Abstract
Despite decades of efforts to develop a pharmacotherapy for cocaine abuse treatment, there is still no FDA-approved treatment of diseases associated with this commonly abused drug. Our previously designed highly efficient cocaine hydrolases (CocHs) and the corresponding Fc-fusion proteins (e.g., CocH3-Fc) are recognized as potentially promising therapeutic enzyme candidates for cocaine abuse treatment, but all with limited biological half-lives. In order to prolong the biological half-life and, thus, decrease the required frequency of the enzyme administration for cocaine abuse treatment, we have modeled the Fc-fusion CocH binding with neonatal Fc receptor (FcRn) in the present study. This approach led to the design and testing of CocH3-Fc(M6), a CocH3-Fc mutant with nearly 100-fold increased binding affinity: from Kd = ~ 4 μM to Kd = 43 nM. As a result, CocH3-Fc(M6) indeed revealed a markedly prolonged biological half-life (t1/2 = 206 ± 7 h or ~ 9 days) in rats, longer than other known Fc-fusion protein drugs such as abatacept and alefacept (for other therapeutic purposes) in the same species (rats). It has been demonstrated that a single dose of 3 mg/kg CocH3-Fc(M6) effectively blocked 20 mg/kg cocaine-induced hyperactivity on day 18 after CocH3-Fc(M6) administration. This is the first attempt to rationally design long-acting Fc-fusion enzyme mutant based on combined computational modeling and experimental measurement of the Fc-fusion CocH binding with FcRn. The similar structure-based design strategy may be used to prolong the biological half-lives of other Fc-fusion protein drugs.
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Affiliation(s)
- Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Xiabin Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Kyungbo Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Ting Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Haifeng Huang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Shuo Zhou
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Jinling Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Zhenyu Jin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA. .,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky, 40536, USA.
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Zheng X, Chen X, Zhang T, Zhan M, Zhan CG, Zheng F. Catalytic activities of cocaine hydrolases against the most toxic cocaine metabolite norcocaethylene. Org Biomol Chem 2020; 18:1968-1977. [PMID: 32101217 PMCID: PMC7362898 DOI: 10.1039/c9ob02762a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A majority of cocaine users also consume alcohol. The concurrent use of cocaine and alcohol produces the pharmacologically active metabolites cocaethylene and norcocaethylene, in addition to norcocaine. Both cocaethylene and norcocaethylene are more toxic than cocaine itself. Hence, a truly valuable cocaine-metabolizing enzyme for cocaine abuse/overdose treatment should be effective for the hydrolysis of not only cocaine, but also its metabolites norcocaine, cocaethylene, and norcocaethylene. However, there has been no report on enzymes capable of hydrolyzing norcocaethylene (the most toxic metabolite of cocaine). The catalytic efficiency parameters (kcat and KM) of human butyrylcholinesterase (BChE) and two mutants (known as cocaine hydrolases E14-3 and E12-7) against norcocaethylene have been characterized in the present study for the first time, and they are compared with those against cocaine. According to the obtained kinetic data, wild-type human BChE showed a similar catalytic efficiency against norcocaethylene (kcat = 9.5 min-1, KM = 11.7 μM, and kcat/KM = 8.12 × 105 M-1 min-1) to that against (-)-cocaine (kcat = 4.1 min-1, KM = 4.5 μM, and kcat/KM = 9.1 × 105 M-1 min-1). E14-3 and E12-7 showed an improved catalytic activity against norcocaethylene compared to wild-type BChE. E12-7 showed a 39-fold improved catalytic efficiency against norcocaethylene (kcat = 210 min-1, KM = 6.6 μM, and kcat/KM = 3.18 × 107 M-1 min-1). It has been demonstrated that E12-7 as an exogenous enzyme can efficiently metabolize norcocaethylene in rats.
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Affiliation(s)
- Xirong Zheng
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
| | - Xiabin Chen
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
| | - Ting Zhang
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
| | - Max Zhan
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
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de Lima Feltraco Lizot L, da Silva ACC, Bastiani MF, Hahn RZ, Bulcão R, Perassolo MS, Antunes MV, Linden R. Simultaneous determination of cocaine, ecgonine methyl ester, benzoylecgonine, cocaethylene and norcocaine in dried blood spots by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Forensic Sci Int 2019; 298:408-416. [DOI: 10.1016/j.forsciint.2019.03.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 12/29/2022]
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10
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Munir S, Habib R, Awan S, Bibi N, Tanveer A, Batool S, Nurulain SM. Biochemical Analysis and Association of Butyrylcholinesterase SNPs rs3495 and rs1803274 with Substance Abuse Disorder. J Mol Neurosci 2019; 67:445-455. [PMID: 30707402 DOI: 10.1007/s12031-018-1251-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 12/26/2018] [Indexed: 12/12/2022]
Abstract
Addiction is a complex mental and behavioral disorder that changes the neurochemistry and physiology of the brain. Genetics also plays a significant role in the pathophysiology of addiction. Butyrylcholinesterase (BChE), a cholinergic enzyme, has been implicated in the metabolism of various drugs, including cocaine, and an association between single-nucleotide polymorphisms (SNPs) of the butyrylcholinesterase gene (BCHE) and neuronal disorders has been reported. We report here the first investigation to be conducted on the status of BChE activity and the potential association of two BCHE gene SNPs, rs3495 (c.*189G > A) and rs1803274 (c.1699G>A, p.Ala567Thr, K-variant), with addiction vulnerability in heroin, hashish and polydrug users. Seventy-five individuals with an addiction to heroin, hashish and/or polydrug use were recruited to this study. BChE levels in the plasma were determined by Ellman's principle. SNPs were genotyped by standard procedures, followed by Sanger sequencing. Plasma BChE levels were found to be significantly higher (p ≤ 0.05) in addicts (mean ± standard error of the mean 0.031 ± 0.004 μmol/L/min; 95% confidence interval [CI] 0.024-0.038) than in non-addicts (controls) (0.014 ± 0.001 μmol/L/min; 95% CI 0.012-0.017). Statistical significant differences were also observed between the addicted cohorts. A statistically significant association for both SNPs (rs3495 and rs1803274) was not observed in addicted subjects tested in the dominant, recessive and allele genetic models, but trends of variations of the rs3495 risk G allele were noted. The authors conclude that BChE plays significant roles in addiction pathophysiology as increased BChE activity in blood samples obtained from the cohorts with addiction was evident. Further studies in this direction may provide novel approaches for the treatment of addiction, but studies with a larger sample size and different ethnic groups are warranted for broader conclusions to be drawn.
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Affiliation(s)
- Sadaf Munir
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Rabia Habib
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan.
| | - Sliha Awan
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Nazia Bibi
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Arooj Tanveer
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Sajida Batool
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Syed M Nurulain
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan.
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Chen X, Zheng X, Ding K, Zhou Z, Zhan CG, Zheng F. A quantitative LC-MS/MS method for simultaneous determination of cocaine and its metabolites in whole blood. J Pharm Biomed Anal 2017; 134:243-251. [PMID: 27923200 PMCID: PMC5196007 DOI: 10.1016/j.jpba.2016.11.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/08/2016] [Accepted: 11/11/2016] [Indexed: 10/20/2022]
Abstract
As new metabolic pathways of cocaine were recently identified, a high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously determine cocaine and nine cocaine-related metabolites in whole blood samples. One-step solid phase extraction was used to extract all of the ten compounds and corresponding internal standards from blood samples. All compounds and internal standards extracted were separated on an Atlantis T3 (100Å, 3μm, 2.1mm×150mm I.D) column and detected in positive ion and high sensitivity mode with multiple reaction monitoring. This method was validated for its sensitivity, linearity, specificity, accuracy, precision, recovery, and stability. All of the ten compounds were quantifiable ranging from the lower limit of quantification (LLOQs) of ∼10nM (1.9-3.2ng/ml) to ∼1000nM (190-320ng/ml) without any interfering substance. Accuracy and precision were determined, and both of them were within the acceptance criteria of the United States (US) Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The recovery was above 66.7% for all compounds. Stability tests demonstrated the stability of compounds under different storage conditions in whole blood samples. The method was successfully applied to a pharmacokinetic study with co-administration of cocaine and alcohol in rats.
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Affiliation(s)
- Xiabin Chen
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States
| | - Xirong Zheng
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States
| | - Kai Ding
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States
| | - Ziyuan Zhou
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States.
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, United States.
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Zhang Y, Huang X, Han K, Zheng F, Zhan CG. Free energy profiles of cocaine esterase-cocaine binding process by molecular dynamics and potential of mean force simulations. Chem Biol Interact 2016; 259:142-147. [PMID: 27163853 DOI: 10.1016/j.cbi.2016.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/29/2016] [Accepted: 05/05/2016] [Indexed: 11/29/2022]
Abstract
The combined molecular dynamics (MD) and potential of mean force (PMF) simulations have been performed to determine the free energy profile of the CocE)-(+)-cocaine binding process in comparison with that of the corresponding CocE-(-)-cocaine binding process. According to the MD simulations, the equilibrium CocE-(+)-cocaine binding mode is similar to the CocE-(-)-cocaine binding mode. However, based on the simulated free energy profiles, a significant free energy barrier (∼5 kcal/mol) exists in the CocE-(+)-cocaine binding process whereas no obvious free energy barrier exists in the CocE-(-)-cocaine binding process, although the free energy barrier of ∼5 kcal/mol is not high enough to really slow down the CocE-(+)-cocaine binding process. In addition, the obtained free energy profiles also demonstrate that (+)-cocaine and (-)-cocaine have very close binding free energies with CocE, with a negligible difference (∼0.2 kcal/mol), which is qualitatively consistent with the nearly same experimental KM values of the CocE enzyme for (+)-cocaine and (-)-cocaine. The consistency between the computational results and available experimental data suggests that the mechanistic insights obtained from this study are reasonable.
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Affiliation(s)
- Yuxin Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, PR China; Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Xiaoqin Huang
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Keli Han
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, PR China
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
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13
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Abstract
Cocaine abuse is a world-wide public health and social problem without a US Food and Drug Administration-approved medication. An ideal anticocaine medication would accelerate cocaine metabolism, producing biologically inactive metabolites by administration of an efficient cocaine-specific exogenous enzyme. Our recent studies have led to the discovery of the desirable, highly efficient cocaine hydrolases (CocHs) that can efficiently detoxify and inactivate cocaine without affecting normal functions of the CNS. Preclinical and clinical data have demonstrated that these CocHs are safe for use in humans and are effective for accelerating cocaine metabolism. However, the actual therapeutic use of a CocH in cocaine addiction treatment is limited by its short biological half-life (e.g., 8 h or shorter in rats). Here we demonstrate a novel CocH form, a catalytic antibody analog, which is a fragment crystallizable (Fc)-fused CocH dimer (CocH-Fc) constructed by using CocH to replace the Fab region of human IgG1. The CocH-Fc not only has a high catalytic efficiency against cocaine but also, like an antibody, has a considerably longer biological half-life (e.g., ∼107 h in rats). A single dose of CocH-Fc was able to accelerate cocaine metabolism in rats even after 20 d and thus block cocaine-induced hyperactivity and toxicity for a long period. Given the general observation that the biological half-life of a protein drug is significantly longer in humans than in rodents, the CocH-Fc reported in this study could allow dosing once every 2-4 wk, or longer, for treatment of cocaine addiction in humans.
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Kinetic characterization of human butyrylcholinesterase mutants for the hydrolysis of cocaethylene. Biochem J 2014; 460:447-57. [PMID: 24870023 DOI: 10.1042/bj20140360] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It is known that the majority of cocaine users also consume alcohol. Alcohol can react with cocaine to produce a significantly more cytotoxic compound, cocaethylene. Hence a truly valuable cocaine-metabolizing enzyme as treatment for cocaine abuse/overdose should be efficient for not only cocaine itself, but also cocaethylene. The catalytic parameters (kcat and KM) of human BChE (butyrylcholinesterase) and two mutants (known as cocaine hydrolases E14-3 and E12-7) for cocaethylene are characterized in the present study, for the first time, in comparison with those for cocaine. On the basis of the obtained kinetic data, wild-type human BChE has a lower catalytic activity for cocaethylene (kcat=3.3 min(-1), KM=7.5 μM and kcat/KM=4.40 × 10(5) M(-1)·min(-1)) compared with its catalytic activity for (-)-cocaine. E14-3 and E12-7 have a considerably improved catalytic activity against cocaethylene compared with the wild-type BChE. E12-7 is identified as the most efficient enzyme for hydrolysing cocaethylene in addition to its high activity for (-)-cocaine. E12-7 has an 861-fold improved catalytic efficiency for cocaethylene (kcat=3600 min(-1), KM=9.5 μM and kcat/KM=3.79 × 10(8) M(-1)·min(-1)). It has been demonstrated that E12-7 as an exogenous enzyme can indeed rapidly metabolize cocaethylene in rats. Further kinetic modelling has suggested that E12-7 with an identical concentration as that of the endogenous BChE in human plasma can effectively eliminate (-)-cocaine, cocaethylene and norcocaine in simplified kinetic models of cocaine abuse and overdose associated with the concurrent use of cocaine and alcohol.
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Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine. Biochem J 2014; 457:197-206. [PMID: 24125115 DOI: 10.1042/bj20131100] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It has been known that cocaine produces its toxic and physiological effects through not only cocaine itself, but also norcocaine formed from cocaine oxidation catalysed by microsomal CYP (cytochrome P450) 3A4 in the human liver. The catalytic parameters (kcat and Km) of human BChE (butyrylcholinesterase) and its three mutants (i.e. A199S/S287G/A328W/Y332G, A199S/F227A/S287G/A328W/E441D and A199S/F227A/S287G/A328W/Y332G) for norcocaine have been characterized in the present study for the first time and compared with those for cocaine. On the basis of the obtained kinetic data, wild-type human BChE has a significantly lower catalytic activity for norcocaine (kcat=2.8 min(-1), Km=15 μM and kcat/Km=1.87 × 10(5) M(-1)·min(-1)) compared with its catalytic activity for (-)-cocaine. The BChE mutants examined in the present study have considerably improved catalytic activities against both cocaine and norcocaine compared with the wild-type enzyme. Within the enzymes examined in the present study, the A199S/F227A/S287G/A328W/Y332G mutant (CocH3) is identified as the most efficient enzyme for hydrolysing both cocaine and norcocaine. CocH3 has a 1080-fold improved catalytic efficiency for norcocaine (kcat=2610 min(-1), Km=13 μM and kcat/Km=2.01 × 10(8) M(-1)·min(-1)) and a 2020-fold improved catalytic efficiency for cocaine. It has been demonstrated that CocH3 as an exogenous enzyme can rapidly metabolize norcocaine, in addition to cocaine, in rats. Further kinetic modelling has suggested that CocH3 with an identical concentration with that of the endogenous BChE in human plasma can effectively eliminate both cocaine and norcocaine in a simplified kinetic model of cocaine abuse.
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16
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Fang L, Zheng F, Zhan CG. A model of glycosylated human butyrylcholinesterase. MOLECULAR BIOSYSTEMS 2014; 10:348-54. [PMID: 24327294 PMCID: PMC3947857 DOI: 10.1039/c3mb70313d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human butyrylcholinesterase (BChE) and its mutants have shown great potential in treating cocaine overdose and addiction. In order to effectively suppress cocaine reward in the brain for a long period of time after an exogenous cocaine hydrolase administration, the therapeutic enzyme should have not only a high catalytic efficiency against cocaine, but also a sufficiently long circulation time. It has been known that PEGylation (covalent attachment of polyethylene glycol) modification of a therapeutic protein can prolong the biological half-life of the protein without affecting its biological function. However, the asparagine-linked glycans on the surface of glycosylated BChE may interfere with the PEGylation modification. In this study, we built a three-dimensional (3D) model of glycosylated human BChE to investigate the influence of glycans on the PEGylation modification. Glycans did not change the overall stability of the BChE structure, but could increase the flexibility of some local structures. For further evaluating the accessibility of the PEGylation reaction sites, particularly lysine residues, on the protein surface, we calculated the Solvent Accessible Surface Areas (SASAs) of these residues. The results indicate that some lysine residues show a significant decrease in SASA due to the direct or indirect influence of their surrounding glycans. The results also indicate that PEGylation reaction agents with smaller functional groups could have a better chance to react with lysine residues. This investigation provides a structural basis for rational engineering of human BChE and its mutants as therapeutic candidates.
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Affiliation(s)
- Lei Fang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
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17
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Hou S, Xue L, Yang W, Fang L, Zheng F, Zhan CG. Substrate selectivity of high-activity mutants of human butyrylcholinesterase. Org Biomol Chem 2013; 11:7477-85. [PMID: 24077614 PMCID: PMC3836059 DOI: 10.1039/c3ob41713a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cocaine is one of the most addictive drugs, and there is still no FDA (Food and Drug Administration)-approved medication specific for cocaine abuse. A promising therapeutic strategy is to accelerate cocaine metabolism, producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. cocaine hydrolysis catalyzed by butyrylcholinesterase (BChE) in plasma. However, the native BChE has a low catalytic efficiency against the abused cocaine, i.e. (-)-cocaine. Our recently designed and discovered A199S/F227A/S287G/A328W/Y332G mutant and other mutants of human BChE have a considerably improved catalytic efficiency against (-)-cocaine. In the present study, we carried out both computational modeling and experimental kinetic analysis on the catalytic activities of these promising new BChE mutants against other known substrates, including neurotransmitter acetylcholine (ACh), acetylthiocholine (ATC), butyrylthiocholine (BTC), and (+)-cocaine, in comparison with the corresponding catalytic activity against (-)-cocaine. Both the computational modeling and kinetic analysis have consistently revealed that all the examined amino acid mutations only considerably improve the catalytic efficiency of human BChE against (-)-cocaine, without significantly improving the catalytic efficiency of the enzyme against any of the other substrates examined. In particular, all the examined BChE mutants have a slightly lower catalytic efficiency against neurotransmitter ACh compared to the wild-type BChE. This observation gives us confidence in developing an anti-cocaine enzyme therapy by using one of these BChE mutants, particularly the A199S/F227A/S287G/A328W/Y332G mutant.
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Affiliation(s)
- Shurong Hou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
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18
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Zheng F, Zhan CG. Modeling of pharmacokinetics of cocaine in human reveals the feasibility for development of enzyme therapies for drugs of abuse. PLoS Comput Biol 2012; 8:e1002610. [PMID: 22844238 PMCID: PMC3406004 DOI: 10.1371/journal.pcbi.1002610] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 05/29/2012] [Indexed: 12/05/2022] Open
Abstract
A promising strategy for drug abuse treatment is to accelerate the drug metabolism by administration of a drug-metabolizing enzyme. The question is how effectively an enzyme can actually prevent the drug from entering brain and producing physiological effects. In the present study, we have developed a pharmacokinetic model through a combined use of in vitro kinetic parameters and positron emission tomography data in human to examine the effects of a cocaine-metabolizing enzyme in plasma on the time course of cocaine in plasma and brain of human. Without an exogenous enzyme, cocaine half-lives in both brain and plasma are almost linearly dependent on the initial cocaine concentration in plasma. The threshold concentration of cocaine in brain required to produce physiological effects has been estimated to be 0.22±0.07 µM, and the threshold area under the cocaine concentration versus time curve (AUC) value in brain (denoted by AUC2∞) required to produce physiological effects has been estimated to be 7.9±2.7 µM·min. It has been demonstrated that administration of a cocaine hydrolase/esterase (CocH/CocE) can considerably decrease the cocaine half-lives in both brain and plasma, the peak cocaine concentration in brain, and the AUC2∞. The estimated maximum cocaine plasma concentration which a given concentration of drug-metabolizing enzyme can effectively prevent from entering brain and producing physiological effects can be used to guide future preclinical/clinical studies on cocaine-metabolizing enzymes. Understanding of drug-metabolizing enzymes is key to the science of pharmacokinetics. The general insights into the effects of a drug-metabolizing enzyme on drug kinetics in human should be valuable also in future development of enzyme therapies for other drugs of abuse. In this computational study, we have examined, for the first time, the potential effects of a drug-metabolizing enzyme on drug pharmacokinetics in human, showing that a high-activity drug-metabolizing enzyme can completely/effectively prevent the drug of abuse from entering brain to produce physiological effects. Based on this encouraging insight, it is feasible to develop enzyme therapies for drugs of abuse. Through pharmacokinetic modeling, we have demonstrated that, without an exogenous enzyme, the drug half-lives in both brain and plasma are almost linearly dependent on the initial drug concentration in plasma. This finding indicates that one may not simply say the half-life of a drug without clearly indicating the actual dose condition. We have also demonstrated for the first time how a high-activity drug-metabolizing enzyme can considerably decrease the peak concentration of drug in brain and drug half-lives in both brain and plasma. In addition, we have calculated the minimum (threshold) concentration of cocaine in brain required to produce physiological effects. The predicted threshold concentration, along with all of the general insights obtained in this study, will provide a rational base for future design of further experimental studies required for the enzyme therapy development.
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Affiliation(s)
- Fang Zheng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
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19
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Accelerating cocaine metabolism as an approach to the treatment of cocaine abuse and toxicity. Future Med Chem 2012; 4:163-75. [PMID: 22300096 DOI: 10.4155/fmc.11.181] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
One pharmacokinetic approach to the treatment of cocaine abuse and toxicity involves the development of compounds that can be safely administered to humans and that accelerate the metabolism of cocaine to inactive components. Catalytic antibodies have been developed and shown to accelerate cocaine metabolism, but their catalytic efficiency for cocaine is relatively low. Mutations of human butyrylcholinesterase and a bacterial cocaine esterase found in the soil of coca plants have also been developed. These compounds accelerate cocaine metabolism and antagonize the behavioral and toxic effects of cocaine in animal models. Of these two approaches, the human butyrylcholinesterase mutants show the most immediate promise as they would not be expected to evoke an immune response in humans.
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Abstract
The pharmacokinetic treatment strategy targets the drug molecule itself, aiming to reduce drug concentration at the site of action, thereby minimizing any pharmacodynamic effect. This approach might be useful in the treatment of acute drug toxicity/overdose and in the long-term treatment of addiction. Phase IIa controlled clinical trials with anticocaine and antinicotine vaccines have shown good tolerability and some efficacy, but Phase IIb and III trials have been disappointing because of the failure to generate adequate antibody titers in most participants. Monoclonal antibodies against cocaine, methamphetamine and phencyclidine have shown promise in animal studies, as has enhancing cocaine metabolism with genetic variants of human butyrylcholinesterase, with a bacterial esterase, and with catalytic monoclonal antibodies. Pharmacokinetic treatments offer potential advantages in terms of patient adherence, absence of medication interactions and benefit for patients who cannot take standard medications.
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Affiliation(s)
- David A Gorelick
- Chemistry & Drug Metabolism Section Intramural Research Program, National Institute on Drug Abuse, NIH, 251 Bayview Boulevard, Baltimore, MD 21224, USA.
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Xue L, Ko MC, Tong M, Yang W, Hou S, Fang L, Liu J, Zheng F, Woods JH, Tai HH, Zhan CG. Design, preparation, and characterization of high-activity mutants of human butyrylcholinesterase specific for detoxification of cocaine. Mol Pharmacol 2011; 79:290-7. [PMID: 20971807 PMCID: PMC3033707 DOI: 10.1124/mol.110.068494] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Accepted: 10/22/2010] [Indexed: 11/22/2022] Open
Abstract
Cocaine is a widely abused drug without a U.S. Food and Drug Administration-approved medication. There is a recognized, promising anticocaine medication to accelerate cocaine metabolism, producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway [i.e., cocaine hydrolysis catalyzed by butyrylcholinesterase (BChE) in plasma]. An ideal, therapeutically valuable mutant of human BChE should have not only a significantly improved catalytic activity against (-)-cocaine but also certain selectivity for (-)-cocaine over neurotransmitter acetylcholine (ACh), such that one would not expect systemic administration of the BChE mutant to interrupt cholinergic transmission. The present study accounting for the mutation-caused changes of the catalytic activities of BChE against both (-)-cocaine and ACh by means of molecular modeling and site-directed mutagenesis has led to identification of three BChE mutants that have not only a considerably improved catalytic efficiency against (-)-cocaine but also the desirable selectivity for (-)-cocaine over ACh. Two representative BChE mutants have been confirmed to be potent in actual protection of mice from acute toxicity (convulsion and lethality) of a lethal dose of cocaine (180 mg/kg). Pretreatment with the BChE mutant (i.e., 1 min before cocaine administration) dose-dependently protected mice against cocaine-induced convulsions and lethality. In particular, all mice pretreated with the mutant (e.g., 0.02 mg or more of A199S/F227A/S287G/A328W/E441D BChE) survived. The in vivo data reveal the primary factor (i.e., the relative catalytic efficiency), determining the efficacy in practical protection of mice from the acute cocaine toxicity and future direction for further improving the efficacy of the enzyme in the cocaine overdose treatment.
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Affiliation(s)
- Liu Xue
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street Lexington, KY 40536, USA
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Effects of cocaine hydrolase on cocaine self-administration under a PR schedule and during extended access (escalation) in rats. Psychopharmacology (Berl) 2011; 213:817-29. [PMID: 20972552 PMCID: PMC3631565 DOI: 10.1007/s00213-010-2040-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 09/30/2010] [Indexed: 10/18/2022]
Abstract
RATIONALE AND OBJECTIVES Previously, Albu-CocH, a cocaine hydrolase derived from human butyrylcholinesterase, blocked cocaine-induced reinstatement of drug seeking in rats. In the present study, rats were treated with Albu-CocH while self-administering cocaine under a progressive ratio (PR) schedule during 2-h sessions and under a fixed-ratio 1 (FR 1) schedule during 6-h sessions. METHODS In experiment 1, rats were treated with saline or Albu-CocH (2 or 4 mg/kg) before a single 2-h cocaine (0.2 mg/kg) self-administration (PR) session. In experiment 2, rats were treated with Albu-CocH or saline for the first seven of the 21-day 6-h sessions prior to cocaine (0.2 or 0.4 mg/kg) self-administration sessions (FR 1). RESULTS In experiment 1, Albu-CocH (vs saline) reduced cocaine infusions immediately following treatment compared with sessions pretreatment and posttreatment. In experiment 2, the Albu-CocH-treated groups (vs saline) showed an initial twofold to threefold increase in 0.2 and 0.4 mg/kg cocaine infusions over the 7 days of treatment, but they decreased to the infusion levels of saline controls by day 7. Cocaine (0.4 mg/kg) intake in the saline-treated group was elevated during the last 3 days of 6-h access compared with the first 3 days, indicating an escalation effect. Responding for 0.4 mg/kg (but not 0.2 mg/kg) cocaine during 2-h sessions after the 21 days of 6-h access was elevated in the saline groups (compared with 2-h sessions before long access) but not in the Albu-CocH-treated groups. CONCLUSIONS Albu-CocH decreased cocaine infusions under the PR schedule, indicating a reduced reward value of cocaine (experiment 1). However, Albu-CocH, compared with saline, temporarily increased cocaine infusions during long access. The post-long access 2-h cocaine intake was not increased in the Albu-CocH-treated groups as it was in the saline-treated groups. Albu-CocH is an effective agent for reducing cocaine reward under conditions of low cocaine exposure and chronic treatment.
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Abstract
“Recent progress in the study of cocaine-metabolizing enzymes demonstrates that enzyme-therapy approaches using appropriately designed enzymes show promise for the treatment of drug overdose and addiction.”
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Affiliation(s)
- Fang Zheng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Chang-Guo Zhan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
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Effects of cocaine esterase following its repeated administration with cocaine in mice. Drug Alcohol Depend 2009; 101:202-9. [PMID: 19217723 PMCID: PMC2693214 DOI: 10.1016/j.drugalcdep.2009.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 12/29/2008] [Accepted: 01/15/2009] [Indexed: 11/21/2022]
Abstract
BACKGROUND A bacterial cocaine esterase (CocE) produces robust protection and reversal of cocaine toxicity. The aim of this study was to investigate how effectiveness of CocE was changed following its repeated administration together with cocaine. METHODS Cocaine toxicity was quantified by measuring the occurrence of convulsions and lethality in mice. Immunologic responses of CocE were determined using ELISA. In the protection experiment, i.v. CocE 0.3mg was given 1min before a lethal dose of i.p. cocaine 180mg/kg. In the rescue experiment, i.v. CocE 0.3mg was given 1min after the occurrence of convulsions elicited by i.p. cocaine 100mg/kg. In both treatment paradigms, four trials were conducted in the same animals with a 2-week interval. RESULTS CocE retained its effectiveness to protect or rescue mice during the first two trials and these mice did not show an immune response. In contrast, CocE's effectiveness was gradually reduced in the last two trials, accompanied by 10- and 100-fold increases in anti-CocE antibody titers. Nevertheless, effectiveness of CocE could be partially recovered by increasing the dose of CocE. In addition, escalating the dose of CocE from the minimum effective dose for repeated administration could also retain CocE's effectiveness longer and slow the production of anti-CocE antibodies. CONCLUSIONS These results indicate that CocE is a weak antigen and it can maintain its protective and rescuing ability initially against cocaine-induced toxicity. Decreased effectiveness of CocE following repeated use can be partially improved by adjusting the dose and frequency of CocE treatment.
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