Fang Zheng

Publications of Fang Zheng

• Cocaine esterase-cocaine binding process and the free energy profiles by molecular dynamics and potential of mean force simulations.

  Authors: Xiaoqin Huang, Xinyun Zhao, Fang Zheng, Chang-Guo Zhan

  The journal of physical chemistry. B. 03/2012; 116(10):3361-8.

  The combined molecular dynamics (MD) and potential of mean force (PMF) simulations have been performed to determine the free energy profiles for the binding process of (-)-cocaine interacting withThe combined molecular dynamics (MD) and potential of mean force (PMF) simulations have been performed to determine the free energy profiles for the binding process of (-)-cocaine interacting with wild-type cocaine esterase (CocE) and its mutants (T172R/G173Q and L119A/L169K/G173Q). According to the MD simulations, the general protein-(-)-cocaine binding mode is not affected by the mutations; e.g.. the benzoyl group of (-)-cocaine is always bound in a subsite composed of aromatic residues W151, W166, F261, and F408 and hydrophobic residue L407, while the carbonyl oxygen on the benzoyl group of (-)-cocaine is hydrogen-bonded with the oxyanion-hole residues Y44 and Y118. According to the PMF-calculated free energy profiles for the binding process, the binding free energies for (-)-cocaine with the wild-type, T172R/G173Q, and L119A/L169K/G173Q CocEs are predicted to be -6.4, -6.2, and -5.0 kcal/mol, respectively. The computational predictions are supported by experimental kinetic data, as the calculated binding free energies are in good agreement with the experimentally derived binding free energies, i.e., -7.2, -6.7, and -4.8 kcal/mol for the wild-type, T172R/G173Q, and L119A/L169K/G173Q, respectively. The reasonable agreement between the computational and experimental data suggests that the PMF simulations may be used as a valuable tool in new CocE mutant design that aims to decrease the Michaelis-Menten constant of the enzyme for (-)-cocaine.

• Are pharmacokinetic approaches feasible for treatment of cocaine addiction and overdose?

  Authors: Fang Zheng, Chang-Guo Zhan

  Future medicinal chemistry. 02/2012; 4(2):125-8.

• Human butyrylcholinesterase-cocaine binding pathway and free energy profiles by molecular dynamics and potential of mean force simulations.

  Authors: Xiaoqin Huang, Fang Zheng, Chang-Guo Zhan

  The journal of physical chemistry. B. 09/2011; 115(38):11254-60.

  In the present study, we have performed combined molecular dynamics and potential of mean force (PMF) simulations to determine the enzyme-substrate (ES) binding pathway and the corresponding freeIn the present study, we have performed combined molecular dynamics and potential of mean force (PMF) simulations to determine the enzyme-substrate (ES) binding pathway and the corresponding free energy profiles for wild-type butyrylcholinesterase (BChE) binding with (-)/(+)-cocaine and for the A328W/Y332G mutant binding with (-)-cocaine. According to the PMF simulations, for each ES binding system, the substrate first binds with the enzyme at a peripheral anionic site around the entrance of the active-site gorge to form the first ES complex (ES1-like) during the binding process. Further evolution from the ES1-like complex to the nonprereactive ES complex is nearly barrierless, with a free energy barrier lower than 1.0 kcal/mol. So, the nonprereactive ES binding process should be very fast. The rate-determining step of the entire ES binding process is the subsequent evolution from the nonprereactive ES complex to the prereactive ES complex. Further accounting for the entire ES binding process, the PMF-based simulations qualitatively reproduced the relative order of the experimentally derived binding free energies (ΔG(bind)), although the simulations systematically overestimated the magnitude of the binding affinity and systematically underestimated the differences between the ΔG(bind) values. The obtained structural and energetic insights into the entire ES binding process provide a valuable base for future rational design of high-activity mutants of BChE as candidates for an enzyme therapy for cocaine overdose and abuse.

• Enzyme-therapy approaches for the treatment of drug overdose and addiction.

  Authors: Fang Zheng, Chang-Guo Zhan

  Future medicinal chemistry. 01/2011; 3(1):9-13.

• Design, synthesis and interaction at the vesicular monoamine transporter-2 of lobeline analogs: potential pharmacotherapies for the treatment of psychostimulant abuse.

  Authors: Peter A Crooks, Guangrong Zheng, Ashish P Vartak, John P Culver, Fang Zheng, David B Horton, Linda P Dwoskin

  Current topics in medicinal chemistry. 11/2010; 11(9):1103-27.

  The vesicular monoamine transporter-2 (VMAT2) is considered as a new target for the development of novel therapeutics to treat psychostimulant abuse. Current information on the structure, functionThe vesicular monoamine transporter-2 (VMAT2) is considered as a new target for the development of novel therapeutics to treat psychostimulant abuse. Current information on the structure, function and role of VMAT2 in psychostimulant abuse are presented. Lobeline, the major alkaloidal constituent of Lobelia inflata, interacts with nicotinic receptors and with VMAT2. Numerous studies have shown that lobeline inhibits both the neurochemical and behavioral effects of amphetamine in rodents, and behavioral studies demonstrate that lobeline has potential as a pharmacotherapy for psychostimulant abuse. Systematic structural modification of the lobeline molecule is described with the aim of improving selectivity and affinity for VMAT2 over neuronal nicotinic acetylcholine receptors and other neurotransmitter transporters. This has led to the discovery of more potent and selective ligands for VMAT2. In addition, a computational neural network analysis of the affinity of these lobeline analogs for VMAT2 has been carried out, which provides computational models that have predictive value in the rational design of VMAT2 ligands and is also useful in identifying drug candidates from virtual libraries for subsequent synthesis and evaluation.

• Design of high-activity mutants of human butyrylcholinesterase against (-)-cocaine: structural and energetic factors affecting the catalytic efficiency.

  Authors: Fang Zheng, Wenchao Yang, Liu Xue, Shurong Hou, Junjun Liu, Chang-Guo Zhan

  Biochemistry. 10/2010; 49(42):9113-9.

  The present study was aimed to explore the correlation between the protein structure and catalytic efficiency of butyrylcholinesterase (BChE) mutants against (-)-cocaine by modeling theThe present study was aimed to explore the correlation between the protein structure and catalytic efficiency of butyrylcholinesterase (BChE) mutants against (-)-cocaine by modeling the rate-determining transition state (TS1), i.e., the transition state for the first step of chemical reaction process, of (-)-cocaine hydrolysis catalyzed by various mutants of human BChE in comparison with the wild type. Molecular modeling of the TS1 structures revealed that mutations on certain nonactive site residues can indirectly affect the catalytic efficiency of the enzyme against (-)-cocaine through enhancing or weakening the overall hydrogen bonding between the carbonyl oxygen of (-)-cocaine benzoyl ester and the oxyanion hole of the enzyme. Computational insights and predictions were supported by the catalytic activity data obtained from wet experimental tests on the mutants of human BChE, including five new mutants reported for the first time. The BChE mutants with at least ∼1000-fold improved catalytic efficiency against (-)-cocaine compared to the wild-type BChE are all associated with the TS1 structures having stronger overall hydrogen bonding between the carbonyl oxygen of (-)-cocaine benzoyl ester and the oxyanion hole of the enzyme. The combined computational and experimental data demonstrate a reasonable correlation relationship between the hydrogen-bonding distances in the TS1 structure and the catalytic efficiency of the enzyme against (-)-cocaine.

• Design, preparation, and characterization of high-activity mutants of human butyrylcholinesterase specific for detoxification of cocaine.

  Authors: Liu Xue, Mei-Chuan Ko, Min Tong, Wenchao Yang, Shurong Hou, Lei Fang, Junjun Liu, Fang Zheng, James H Woods, Hsin-Hsiung Tai, Chang-Guo Zhan

  Molecular pharmacology. 10/2010; 79(2):290-7.

  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, producingCocaine 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.

• Reaction pathway and free energy profile for prechemical reaction step of human butyrylcholinesterase-catalyzed hydrolysis of (-)-cocaine by combined targeted molecular dynamics and potential of mean force simulations.

  Authors: Xiaoqin Huang, Yongmei Pan, Fang Zheng, Chang-Guo Zhan

  The journal of physical chemistry. B. 09/2010; 114(42):13545-54.

  Combined targeted molecular dynamics (TMD) and potential of mean force (PMF) simulations have been carried out to uncover the detailed pathway and determine the corresponding free energy profile forCombined targeted molecular dynamics (TMD) and potential of mean force (PMF) simulations have been carried out to uncover the detailed pathway and determine the corresponding free energy profile for the structural transformation from the nonprereactive butyrylcholinesterase (BChE)-(-)-cocaine binding to the prereactive BChE-(-)-cocaine binding associated with the (-)-cocaine rotation in the binding pocket of BChE. It has been shown that the structural transformation involves two transition states (TS1(rot) and TS2(rot)). TS1(rot) is mainly associated with the deformation of the nonprereactive complex, whereas TS2(rot) is mainly associated with the formation of the prereactive complex. It has also been demonstrated that the A328W/Y332G mutation significantly reduces the steric hindrance for (-)-cocaine rotation in the binding pocket of BChE and, thus, decreases the free energy barrier for the structural transformation from the nonprereactive binding to the prereactive binding. The calculated relative free energy barriers are all consistent with available experimental kinetic data. The new mechanistic insights obtained and the novel computational protocol tested in this study should be valuable for future computational design of high-activity mutants of BChE. The general computational strategy and approach based on the combined TMD and PMF simulations may be also valuable in computational studies of detailed pathways and free energy profiles for other similar mechanistic problems involving ligand rotation or another type of structural transformation in the binding pocket of a protein.

• Free energy perturbation simulation on transition states and high-activity mutants of human butyrylcholinesterase for (-)-cocaine hydrolysis.

  Authors: Wenchao Yang, Yongmei Pan, Lei Fang, Daquan Gao, Fang Zheng, Chang-Guo Zhan

  The journal of physical chemistry. B. 08/2010; 114(33):10889-96.

  A unified computational approach based on free energy perturbation (FEP) simulations of transition states has been employed to calculate the mutation-caused shifts of the free energy change from theA unified computational approach based on free energy perturbation (FEP) simulations of transition states has been employed to calculate the mutation-caused shifts of the free energy change from the free enzyme to the rate-determining transition state for (-)-cocaine hydrolysis catalyzed by the currently most promising series of mutants of human butyrylcholinesterase (BChE) that contain the A199S/A328W/Y332G mutations. The FEP simulations were followed by Michaelis-Menten kinetics analysis determining the individual k(cat) and K(M) values missing for the A199S/F227A/A328W/Y332G mutant in this series. The calculated mutation-caused shifts of the free energy change from the free enzyme to the rate-determining transition state are in good agreement with the experimental kinetic data, demonstrating that the unified computational approach based on the FEP simulations of the transition states may be valuable for future computational design of new BChE mutants with a further improved catalytic efficiency against (-)-cocaine.

• First-Principles Determination of Molecular Conformations of Indolizidine (-)-235B' in Solution.

  Authors: Fang Zheng, Linda P Dwoskin, Peter A Crooks, Chang-Guo Zhan

  Theoretical chemistry accounts. 10/2009; 124(3-4):269-278.

  Indolizidine (-)-235B' is a particularly interesting natural product, as it is the currently known, most potent and subtype-selective open-channel blocker of the alpha4beta2 nicotinic acetylcholineIndolizidine (-)-235B' is a particularly interesting natural product, as it is the currently known, most potent and subtype-selective open-channel blocker of the alpha4beta2 nicotinic acetylcholine receptor (nAChR). In the current study, extensive first-principles electronic structure calculations have been carried out in order to determine the stable molecular conformations and their relative free energies of the protonated and deprotonated states of (-)-235B' in the gas phase, in chloroform, and in aqueous solution. The (1)H and (13)C NMR chemical shifts calculated using the computationally determined dominant molecular conformation of the deprotonated state are all consistent with available experimental NMR spectra of (-)-235B' in chloroform, which suggests that the computationally determined molecular conformations are reasonable. Our computational results reveal for the first time that two geminal H atoms on carbon-3 (C3) of (-)-235B' have remarkably different chemical shifts (i.e. 3.24 and 2.03 ppm). The computational results help one to better understand and analyze the experimental (1)H NMR spectra of (-)-235B'. The finding of remarkably different chemical shifts of two C3 geminal H atoms in a certain molecular conformation of (-)-235B' may also be valuable in analysis of NMR spectra of other related ring-containing compounds. In addition, the pK(a) of (-)-235B' in aqueous solution is predicted to be ~9.7. All of the computational results provide a solid basis for future studies of the microscopic and phenomenological binding of various receptor proteins with the protonated and deprotonated structures of this unique open-channel blocker of alpha4beta2 nAChRs. This computational study also demonstrates how one can appropriately use computational modeling and spectroscopic analysis to address the structural and spectroscopic problems that cannot be addressed by experiments alone.

• QSAR study on maximal inhibition (Imax) of quaternary ammonium antagonists for S-(-)-nicotine-evoked dopamine release from dopaminergic nerve terminals in rat striatum.

  Authors: Fang Zheng, Matthew J McConnell, Chang-Guo Zhan, Linda P Dwoskin, Peter A Crooks

  Bioorganic & medicinal chemistry. 08/2009; 17(13):4477-85.

  Maximal inhibition (I(max)) of the agonist effect is an important pharmacological property of inhibitors that interact with multiple receptor subtypes that are activated by the same agonist and whichMaximal inhibition (I(max)) of the agonist effect is an important pharmacological property of inhibitors that interact with multiple receptor subtypes that are activated by the same agonist and which elicit the same functional response. This report represents the first QSAR study on a set of 66 mono- and bis-quaternary ammonium salts that act as antagonists at neuronal nicotinic acetylcholine receptors mediating nicotine-evoked dopamine release, conducted using multi-linear regression (MLR) and neural network (NN) analysis with the maximal inhibition (I(max)) values of the antagonists as target values. The statistical results for the generated MLR model were: r(2)=0.89, rmsd=9.01, q(2)=0.83 and loormsd=11.1; the statistical results for the generated NN model were: r(2)=0.89, rmsd=8.98, q(2)=0.83 and loormsd=11.2. The maximal inhibition values of the compounds exhibited a good correlation with the predictions made by the QSAR models developed, which provide a basis for rationalizing selection of compounds for synthesis in the discovery of effective and selective second generation inhibitors of nAChRs mediating nicotine-evoked dopamine release.

• Recent progress in protein drug design and discovery with a focus on novel approaches to the development of anti-cocaine medications.

  Authors: Fang Zheng, Chang-Guo Zhan

  Future medicinal chemistry. 06/2009; 1(3):515-28.

  Cocaine is highly addictive and no anti-cocaine medication is currently available. Accelerating cocaine metabolism, producing biologically inactive metabolites, is recognized as an ideal anti-cocaineCocaine is highly addictive and no anti-cocaine medication is currently available. Accelerating cocaine metabolism, producing biologically inactive metabolites, is recognized as an ideal anti-cocaine medication strategy, especially for the treatment of acute cocaine toxicity. However, currently known wild-type enzymes have either too low a catalytic efficiency against the abused cocaine, in other words (-)-cocaine, or the in vivo half-life is too short. Novel computational strategies and design approaches have been developed recently to design and discover thermostable or high-activity mutants of enzymes based on detailed structures and catalytic/inactivation mechanisms. The structure- and mechanism-based computational design efforts have led to the discovery of high-activity mutants of butyrylcholinesterase and thermostable mutants of cocaine esterase as promising anti-cocaine therapeutics. The structure- and mechanism-based computational strategies and design approaches may be used to design high-activity and/or thermostable mutants of many other proteins that have clear therapeutic potentials and to design completely new therapeutic enzymes.

• Free-energy perturbation simulation on transition States and redesign of butyrylcholinesterase.

  Authors: Wenchao Yang, Yongmei Pan, Fang Zheng, Hoon Cho, Hsin-Hsiung Tai, Chang-Guo Zhan

  Biophysical journal. 04/2009; 96(5):1931-8.

  It is recognized that an ideal anti-cocaine treatment is to accelerate cocaine metabolism by producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizingIt is recognized that an ideal anti-cocaine treatment is to accelerate cocaine metabolism by producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e., butyrylcholinesterase (BChE)-catalyzed hydrolysis of cocaine. BChE mutants with a higher catalytic activity against (-)-cocaine are highly desired for use as an exogenous enzyme in humans. To develop a rational design for high-activity mutants, we carried out free-energy perturbation (FEP) simulations on various mutations of the transition-state structures in addition to the corresponding free-enzyme structures by using an extended FEP procedure. The FEP simulations on the mutations of both the free-enzyme and transition-state structures allowed us to calculate the mutation-caused shift of the free-energy change from the free enzyme (BChE) to the transition state, and thus to theoretically predict the mutation-caused shift of the catalytic efficiency (k(cat)/K(M)). The computational predictions are supported by the kinetic data obtained from the wet experiments, demonstrating that the FEP-based computational design approach is promising for rational design of high-activity mutants of an enzyme. One of the BChE mutants designed and discovered in this study has an approximately 1800-fold improved catalytic efficiency against (-)-cocaine compared to wild-type BChE. The high-activity mutant may be therapeutically valuable.

• Computational neural network analysis of the affinity of N-n-alkylnicotinium salts for the alpha4beta2* nicotinic acetylcholine receptor.

  Authors: Fang Zheng, Guangrong Zheng, A Gabriela Deaciuc, Chang-Guo Zhan, Linda P Dwoskin, Peter A Crooks

  Journal of enzyme inhibition and medicinal chemistry. 02/2009; 24(1):157-68.

  Based on an 85 molecule database, linear regression with different size datasets and an artificial neural network approach have been used to build mathematical relationships to fit experimentallyBased on an 85 molecule database, linear regression with different size datasets and an artificial neural network approach have been used to build mathematical relationships to fit experimentally obtained affinity values (K(i)) of a series of mono- and bis-quaternary ammonium salts from [(3)H]nicotine binding assays using rat striatal membrane preparations. The fitted results were then used to analyze the pattern among the experimental K(i) values of a set of N-n-alkylnicotinium analogs with increasing n-alkyl chain length from 1 to 20 carbons. The affinity of these N-n-alkylnicotinium compounds was shown to parabolically vary with increasing numbers of carbon atoms in the n-alkyl chain, with a local minimum for the C(4) (n-butyl) analogue. A decrease in K(i) value between C(12) and C(13) was also observed. The statistical results for the best neural network fit of the 85 experimental K(i) values are r(2) = 0.84, rmsd = 0.39; r(cv)(2) = 0.68, and loormsd = 0.56. The generated neural network model with the 85 molecule training set may also be of value for future predictions of K(i) values for new virtual compounds, which can then be identified, subsequently synthesized, and tested experimentally.

• Modeling Binding Modes of alpha7 Nicotinic Acetylcholine Receptor with Ligands: The Roles of Gln117 and Other Residues of the Receptor in Agonist Binding.

  Authors: Xiaoqin Huang, Fang Zheng, Clare Stokes, Roger L Papke, Chang-Guo Zhan

  Journal of medicinal chemistry. 02/2009;

• Modeling differential binding of alpha4beta2 nicotinic acetylcholine receptor with agonists and antagonists.

  Authors: Xiaoqin Huang, Fang Zheng, Chang-Guo Zhan

  Journal of the American Chemical Society. 01/2009; 130(49):16691-6.

  Three-dimensional structures of both the open- and closed-channel states of alpha4beta2 receptor have been modeled and used to study their binding with representative agonists and antagonists. TheThree-dimensional structures of both the open- and closed-channel states of alpha4beta2 receptor have been modeled and used to study their binding with representative agonists and antagonists. The obtained binding structures and free energies consistently reveal that antagonists bind more favorably with the closed-channel state and agonists bind more favorably with the open-channel state. The computational insights have led us to propose a computational strategy and protocol predicting whether a receptor ligand is an agonist or antagonist. Using the computational protocol, one only needs to calculate the relative binding free energies for a ligand binding with the open- and closed-channel structures. The ligand is predicted to be an agonist if the binding free energy calculated for the ligand binding with the open-channel state is significantly lower than that for its binding with the closed-channel state. If the binding free energy of a ligand with the open-channel state is higher than that with the closed-channel, the ligand is predicted to be an antagonist. The binding free energies calculated for all of the ligands binding with their most favorable channel states of the receptor are all close to the corresponding experimentally derived binding free energies. The new computational insights obtained and novel computational strategy and protocol proposed in this study are expected to be valuable in structure-based rational design of novel agonists/antagonists of nAChRs as therapeutic agents.

• Modeling Binding Modes of alpha7 Nicotinic Acetylcholine Receptor with Ligands: The Roles of Gln117 and Other Residues of the Receptor in Agonist Binding.

  Authors: Xiaoqin Huang, Fang Zheng, Clare Stokes, Roger Papke, Chang-Guo Zhan

  Journal of medicinal chemistry. 11/2008;

  Extensive molecular docking, molecular dynamics simulations, and binding free energy calculations have been performed to understand how alpha7-specific agonists of nicotinic acetylcholine receptorExtensive molecular docking, molecular dynamics simulations, and binding free energy calculations have been performed to understand how alpha7-specific agonists of nicotinic acetylcholine receptor (nAChR), including AR-R17779 ( 1), GTS-21 ( 4), and 4-OH-GTS-21 ( 5), interact with the alpha7 receptor, leading to important new insights into the receptor-agonist binding. In particular, the cationic head of 4 and 5 has favorable hydrogen bonding and cation-pi interactions with residue Trp149. The computational results have also led us to better understand the roles of Gln117 and other residues in the receptor binding with agonists. The computational predictions are supported by data obtained from wet experimental tests. The new insights into the binding and structure-activity relationship obtained from this study should be valuable for future rational design of more potent and selective agonists of the alpha7 receptor.

• Most efficient cocaine hydrolase designed by virtual screening of transition states.

  Authors: Fang Zheng, Wenchao Yang, Mei-Chuan Ko, Junjun Liu, Hoon Cho, Daquan Gao, Min Tong, Hsin-Hsiung Tai, James H Woods, Chang-Guo Zhan

  Journal of the American Chemical Society. 10/2008; 130(36):12148-55.

  Cocaine is recognized as the most reinforcing of all drugs of abuse. There is no anticocaine medication available. The disastrous medical and social consequences of cocaine addiction have made theCocaine is recognized as the most reinforcing of all drugs of abuse. There is no anticocaine medication available. The disastrous medical and social consequences of cocaine addiction have made the development of an anticocaine medication a high priority. It has been recognized that an ideal anticocaine medication is one that accelerates cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e., cocaine hydrolysis catalyzed by plasma enzyme butyrylcholinesterase (BChE). However, wild-type BChE has a low catalytic efficiency against the abused cocaine. Design of a high-activity enzyme mutant is extremely challenging, particularly when the chemical reaction process is rate-determining for the enzymatic reaction. Here we report the design and discovery of a high-activity mutant of human BChE by using a novel, systematic computational design approach based on transition-state simulations and activation energy calculations. The novel computational design approach has led to discovery of the most efficient cocaine hydrolase, i.e., a human BChE mutant with an approximately 2000-fold improved catalytic efficiency, promising for therapeutic treatment of cocaine overdose and addiction as an exogenous enzyme in human. The encouraging discovery resulted from the computational design not only provides a promising anticocaine medication but also demonstrates that the novel, generally applicable computational design approach is promising for rational enzyme redesign and drug discovery.

• Structure-and-mechanism-based design and discovery of therapeutics for cocaine overdose and addiction.

  Authors: Fang Zheng, Chang-Guo Zhan

  Organic & biomolecular chemistry. 04/2008; 6(5):836-43.

  (-)-Cocaine is a widely abused drug and there is currently no available anti-cocaine therapeutic. Promising agents, such as anti-cocaine catalytic antibodies and high-activity mutants of human(-)-Cocaine is a widely abused drug and there is currently no available anti-cocaine therapeutic. Promising agents, such as anti-cocaine catalytic antibodies and high-activity mutants of human butyrylcholinesterase (BChE), for therapeutic treatment of cocaine overdose have been developed through structure-and-mechanism-based design and discovery. In particular, a unique computational design strategy based on the modeling and simulation of the rate-determining transition state has been developed and used to design and discover desirable high-activity mutants of BChE. One of the discovered high-activity mutants of BChE has a approximately 456-fold improved catalytic efficiency against (-)-cocaine. The encouraging outcome of the structure-and-mechanism-based design and discovery effort demonstrates that the unique computational design approach based on transition state modeling and simulation is promising for rational enzyme redesign and drug discovery. The general approach of the structure-and-mechanism-based design and discovery may be used to design high-activity mutants of any enzyme or catalytic antibody.

• Rational design of an enzyme mutant for anti-cocaine therapeutics.

  Authors: Fang Zheng, Chang-Guo Zhan

  Journal of computer-aided molecular design. 12/2007;

  (-)-Cocaine is a widely abused drug and there is no available anti-cocaine therapeutic. The disastrous medical and social consequences of cocaine addiction have made the development of an effective(-)-Cocaine is a widely abused drug and there is no available anti-cocaine therapeutic. The disastrous medical and social consequences of cocaine addiction have made the development of an effective pharmacological treatment a high priority. An ideal anti-cocaine medication would be to accelerate (-)-cocaine metabolism producing biologically inactive metabolites. The main metabolic pathway of cocaine in body is the hydrolysis at its benzoyl ester group. Reviewed in this article is the state-of-the-art computational design of high-activity mutants of human butyrylcholinesterase (BChE) against (-)-cocaine. The computational design of BChE mutants have been based on not only the structure of the enzyme, but also the detailed catalytic mechanisms for BChE-catalyzed hydrolysis of (-)-cocaine and (+)-cocaine. Computational studies of the detailed catalytic mechanisms and the structure-and-mechanism-based computational design have been carried out through the combined use of a variety of state-of-the-art techniques of molecular modeling. By using the computational insights into the catalytic mechanisms, a recently developed unique computational design strategy based on the simulation of the rate-determining transition state has been employed to design high-activity mutants of human BChE for hydrolysis of (-)-cocaine, leading to the exciting discovery of BChE mutants with a considerably improved catalytic efficiency against (-)-cocaine. One of the discovered BChE mutants (i.e., A199S/S287G/A328W/Y332G) has a approximately 456-fold improved catalytic efficiency against (-)-cocaine. The encouraging outcome of the computational design and discovery effort demonstrates that the unique computational design approach based on the transition-state simulation is promising for rational enzyme redesign and drug discovery.