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Bailey LJ, Sheehy KM, Dominik PK, Liang WG, Rui H, Clark M, Jaskolowski M, Kim Y, Deneka D, Tang WJ, Kossiakoff AA. Locking the Elbow: Improved Antibody Fab Fragments as Chaperones for Structure Determination. J Mol Biol 2017; 430:337-347. [PMID: 29273204 DOI: 10.1016/j.jmb.2017.12.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/05/2017] [Accepted: 12/13/2017] [Indexed: 01/01/2023]
Abstract
Antibody Fab fragments have been exploited with significant success to facilitate the structure determination of challenging macromolecules as crystallization chaperones and as molecular fiducial marks for single particle cryo-electron microscopy approaches. However, the inherent flexibility of the "elbow" regions, which link the constant and variable domains of the Fab, can introduce disorder and thus diminish their effectiveness. We have developed a phage display engineering strategy to generate synthetic Fab variants that significantly reduces elbow flexibility, while maintaining their high affinity and stability. This strategy was validated using previously recalcitrant Fab-antigen complexes where introduction of an engineered elbow region enhanced crystallization and diffraction resolution. Furthermore, incorporation of the mutations appears to be generally portable to other synthetic antibodies and may serve as a universal strategy to enhance the success rates of Fabs as structure determination chaperones.
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Affiliation(s)
- Lucas J Bailey
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Kimberly M Sheehy
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Pawel K Dominik
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Wenguang G Liang
- Ben May Institute for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Huan Rui
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Michael Clark
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Mateusz Jaskolowski
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; University of Gdansk and Medical University of Gdansk, International Faculty of Biotechnology, Gdansk, Poland
| | - Yejoon Kim
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Dawid Deneka
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Krakow, Poland
| | - Wei-Jen Tang
- Ben May Institute for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
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2
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Abstract
The existence of catalytic antibodies has been known for decades. Natural antibodies capable of cleaving nucleic acid, protein, and polysaccharide substrates have been described. Although the discovery of catalytic antibodies initially aroused great interest because of their promise for the development of new catalysts, their enzymatic performance has been disappointing due to low reaction rates. However, in the areas of infection and immunity, where processes often occur over much longer times and involve high antibody concentrations, even low catalytic rates have the potential to influence biological outcomes. In this regard, the presence of catalytic antibodies recognizing host antigens has been associated with several autoimmune diseases. Furthermore, naturally occurring catalytic antibodies to microbial determinants have been correlated with resistance to infection. Recently, there has been substantial interest in harnessing the power of antibody-mediated catalysis against microbial antigens for host defense. Additional work is needed, however, to better understand the prevalence, function, and structural basis of catalytic activity in antibodies. Here we review the available information and suggest that antibody-mediated catalysis is a fertile area for study with broad applications in infection and immunity.
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3
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Abstract
Organophosphonic acids are unique as natural products in terms of stability and mimicry. The C-P bond that defines these compounds resists hydrolytic cleavage, while the phosphonyl group is a versatile mimic of transition-states, intermediates, and primary metabolites. This versatility may explain why a variety of organisms have extensively explored the use organophosphonic acids as bioactive secondary metabolites. Several of these compounds, such as fosfomycin and bialaphos, figure prominently in human health and agriculture. The enzyme reactions that create these molecules are an interesting mix of chemistry that has been adopted from primary metabolism as well as those with no chemical precedent. Additionally, the phosphonate moiety represents a source of inorganic phosphate to microorganisms that live in environments that lack this nutrient; thus, unusual enzyme reactions have also evolved to cleave the C-P bond. This review is a comprehensive summary of the occurrence and function of organophosphonic acids natural products along with the mechanisms of the enzymes that synthesize and catabolize these molecules.
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Affiliation(s)
- Geoff P Horsman
- Department of Chemistry and Biochemistry, Wilfrid Laurier University , Waterloo, Ontario N2L 3C5, Canada
| | - David L Zechel
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
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4
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Chen X, Zheng X, Zhan M, Zhou Z, Zhan CG, Zheng F. Metabolic Enzymes of Cocaine Metabolite Benzoylecgonine. ACS Chem Biol 2016; 11:2186-94. [PMID: 27224254 DOI: 10.1021/acschembio.6b00277] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cocaine is one of the most addictive drugs without a U.S. Food and Drug Administration (FDA)-approved medication. Enzyme therapy using an efficient cocaine-metabolizing enzyme is recognized as the most promising approach to cocaine overdose treatment. The actual enzyme, known as RBP-8000, under current clinical development for cocaine overdose treatment is our previously designed T172R/G173Q mutant of bacterial cocaine esterase (CocE). The T172R/G173Q mutant is effective in hydrolyzing cocaine but inactive against benzoylecgonine (a major, biologically active metabolite of cocaine). Unlike cocaine itself, benzoylecgonine has an unusually stable zwitterion structure resistant to further hydrolysis in the body and environment. In fact, benzoylecgonine can last in the body for a very long time (a few days) and, thus, is responsible for the long-term toxicity of cocaine and a commonly used marker for drug addiction diagnosis in pre-employment drug tests. Because CocE and its mutants are all active against cocaine and inactive against benzoylecgonine, one might simply assume that other enzymes that are active against cocaine are also inactive against benzoylecgonine. Here, through combined computational modeling and experimental studies, we demonstrate for the first time that human butyrylcholinesterase (BChE) is actually active against benzoylecgonine, and that a rationally designed BChE mutant can not only more efficiently accelerate cocaine hydrolysis but also significantly hydrolyze benzoylecgonine in vitro and in vivo. This sets the stage for advanced studies to design more efficient mutant enzymes valuable for the development of an ideal cocaine overdose enzyme therapy and for benzoylecgonine detoxification in the environment.
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Affiliation(s)
- Xiabin Chen
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Xirong Zheng
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Max Zhan
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Ziyuan Zhou
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
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5
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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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Deyev SM, Lebedenko EN, Petrovskaya LE, Dolgikh DA, Gabibov AG, Kirpichnikov MP. Man-made antibodies and immunoconjugates with desired properties: function optimization using structural engineering. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4459] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Crystal structure of two anti-porphyrin antibodies with peroxidase activity. PLoS One 2012; 7:e51128. [PMID: 23240001 PMCID: PMC3519839 DOI: 10.1371/journal.pone.0051128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 10/30/2012] [Indexed: 01/07/2023] Open
Abstract
We report the crystal structures at 2.05 and 2.45 Å resolution of two antibodies, 13G10 and 14H7, directed against an iron(III)-αααβ-carboxyphenylporphyrin, which display some peroxidase activity. Although these two antibodies differ by only one amino acid in their variable λ-light chain and display 86% sequence identity in their variable heavy chain, their complementary determining regions (CDR) CDRH1 and CDRH3 adopt very different conformations. The presence of Met or Leu residues at positions preceding residue H101 in CDRH3 in 13G10 and 14H7, respectively, yields to shallow combining sites pockets with different shapes that are mainly hydrophobic. The hapten and other carboxyphenyl-derivatized iron(III)-porphyrins have been modeled in the active sites of both antibodies using protein ligand docking with the program GOLD. The hapten is maintained in the antibody pockets of 13G10 and 14H7 by a strong network of hydrogen bonds with two or three carboxylates of the carboxyphenyl substituents of the porphyrin, respectively, as well as numerous stacking and van der Waals interactions with the very hydrophobic CDRH3. However, no amino acid residue was found to chelate the iron. Modeling also allows us to rationalize the recognition of alternative porphyrinic cofactors by the 13G10 and 14H7 antibodies and the effect of imidazole binding on the peroxidase activity of the 13G10/porphyrin complexes.
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Brimijoin S. Interception of cocaine by enzyme or antibody delivered with viral gene transfer: a novel strategy for preventing relapse in recovering drug users. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2012; 10:880-91. [PMID: 22229308 DOI: 10.2174/187152711799219398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 11/03/2011] [Accepted: 11/07/2011] [Indexed: 01/08/2023]
Abstract
Recent progress in enzyme engineering has led to versions of human butyrylcholinesterase (BChE) that hydrolyze cocaine efficiently in plasma, reduce concentrations reaching reward neurocircuity in the brain, and weaken behavioral responses to this drug. Along with enzyme advances, increasingly avid anti-cocaine antibodies and potent anti-cocaine vaccines have also been developed. Here we review these developments and consider the potential advantages along with the risks of delivering drug-intercepting proteins via gene transfer approaches to treat cocaine addiction.
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Affiliation(s)
- Stephen Brimijoin
- Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester Minnesota, USA.
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9
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Abstract
Rapid progress in the past decade with re-engineering of human plasma butyrylcholinesterase has led to enzymes that destroy cocaine so efficiently that they prevent or interrupt drug actions in the CNS even though confined to the blood stream. Over the same time window, improved gene-transfer technology has made it possible to deliver such enzymes by endogenous gene transduction at high levels for periods of a year or longer after a single treatment. This article reviews recent advances in this field and considers prospects for development of a robust therapy aimed at aiding recovering drug users avoid addiction relapse.
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10
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Huang X, Gao D, Zhan CG. Computational design of a thermostable mutant of cocaine esterase via molecular dynamics simulations. Org Biomol Chem 2011; 9:4138-43. [PMID: 21373712 PMCID: PMC4365906 DOI: 10.1039/c0ob00972e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cocaine esterase (CocE) has been known as the most efficient native enzyme for metabolizing naturally occurring cocaine. A major obstacle to the clinical application of CocE is the thermoinstability of native CocE with a half-life of only ∼11 min at physiological temperature (37 °C). It is highly desirable to develop a thermostable mutant of CocE for therapeutic treatment of cocaine overdose and addiction. To establish a structure-thermostability relationship, we carried out molecular dynamics (MD) simulations at 400 K on wild-type CocE and previously known thermostable mutants, demonstrating that the thermostability of the active form of the enzyme correlates with the fluctuation (characterized as the root-mean square deviation and root-mean square fluctuation of atomic positions) of the catalytic residues (Y44, S117, Y118, H287, and D259) in the simulated enzyme. In light of the structure-thermostability correlation, further computational modelling including MD simulations at 400 K predicted that the active site structure of the L169K mutant should be more thermostable. The prediction has been confirmed by wet experimental tests showing that the active form of the L169K mutant had a half-life of 570 min at 37 °C, which is significantly longer than those of the wild-type and previously known thermostable mutants. The encouraging outcome suggests that the high-temperature MD simulations and the structure-thermostability relationship may be considered as a valuable tool for the computational design of thermostable mutants of an enzyme.
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Affiliation(s)
- Xiaoqin Huang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536
| | - Daquan Gao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536
| | - Chang-Guo Zhan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536
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11
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Rincón DA, Cordeiro MNDS, Mosquera RA. On the electronic structure of cocaine and its metabolites. J Phys Chem A 2010; 113:13937-42. [PMID: 19908877 DOI: 10.1021/jp9056048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work aims at describing the electronic features of cocaine and how they are modified by the different substituents present in its metabolites. The QTAIM analysis of B3LYP and MP2 electron densities obtained with the 6-311++G** 6d basis set for cocaine and its principal metabolites indicates: (i) its positive charge is shared among the amino hydrogen, those of the methylamino group, and all of the hydrogens attached to the bicycle structure; (ii) the zwitterionic structure of benzoylecgonine can be described as two partial charges of 0.63 au, the negative one shared by the oxygens of the carboxylate group, whereas the positive charge is distributed among all the hydrogens that bear the positive charge in cocaine; (iii) its hydrogen bond is strengthened in the derivatives without benzoyloxy group and is also slightly strengthened as the size of the alkyl ester group at position 2 increases.
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Affiliation(s)
- David A Rincón
- Departamento de Química Física, Universidade de Vigo, Campus Universitario Lagoas-Marcosende 36310 Vigo, Spain
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12
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Pan Y, Gao D, Zhan CG. Modeling the catalysis of anti-cocaine catalytic antibody: competing reaction pathways and free energy barriers. J Am Chem Soc 2008; 130:5140-9. [PMID: 18341277 DOI: 10.1021/ja077972s] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The competing reaction pathways and the corresponding free energy barriers for cocaine hydrolysis catalyzed by an anti-cocaine catalytic antibody, mAb15A10, were studied by using a novel computational strategy based on the binding free energy calculations on the antibody binding with cocaine and transition states. The calculated binding free energies were used to evaluate the free energy barrier shift from the cocaine hydrolysis in water to the antibody-catalyzed cocaine hydrolysis for each reaction pathway. The free energy barriers for the antibody-catalyzed cocaine hydrolysis were predicted to be the corresponding free energy barriers for the cocaine hydrolysis in water plus the calculated free energy barrier shifts. The calculated free energy barrier shift of -6.87 kcal/mol from the dominant reaction pathway of the cocaine benzoyl ester hydrolysis in water to the dominant reaction pathway of the antibody-catalyzed cocaine hydrolysis is in good agreement with the experimentally derived free energy barrier shift of -5.93 kcal/mol. The calculated mutation-caused shifts of the free energy barrier are also reasonably close to the available experimental activity data. The good agreement suggests that the protocol for calculating the free energy barrier shift from the cocaine hydrolysis in water to the antibody-catalyzed cocaine hydrolysis may be used in future rational design of possible high-activity mutants of the antibody as anti-cocaine therapeutics. The general strategy of the free energy barrier shift calculation may also be valuable in studying a variety of chemical reactions catalyzed by other antibodies or proteins through noncovalent bonding interactions with the substrates.
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Affiliation(s)
- Yongmei Pan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, Kentucky 40536, USA
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13
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Zheng F, Zhan CG. Structure-and-mechanism-based design and discovery of therapeutics for cocaine overdose and addiction. Org Biomol Chem 2007; 6:836-43. [PMID: 18292872 DOI: 10.1039/b716268e] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
(-)-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.
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Affiliation(s)
- Fang Zheng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 725 Rose Street, Lexington, KY 40536, USA
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14
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Tanaka F, Jones T, Kubitz D, Lerner RA. Anti-formyl peptide antibodies. Bioorg Med Chem Lett 2007; 17:1943-5. [PMID: 17293112 DOI: 10.1016/j.bmcl.2007.01.082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 01/09/2007] [Indexed: 01/18/2023]
Abstract
Antibodies that selectively bind to N-formylmethionyl leucyl phenylalanine (fMLF, also known as fMLP) have been generated. These antibodies bound to fMLF with higher affinity than to non-formylated peptide MLF: the differences in the binding energies between fMLF and MLF were 1.4->2.1 kcal/mol.
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Affiliation(s)
- Fujie Tanaka
- Department of Molecular Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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15
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McKenzie KM, Mee JM, Rogers CJ, Hixon MS, Kaufmann GF, Janda KD. Identification and characterization of single chain anti-cocaine catalytic antibodies. J Mol Biol 2006; 365:722-31. [PMID: 17084858 PMCID: PMC1828637 DOI: 10.1016/j.jmb.2006.10.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Revised: 10/07/2006] [Accepted: 10/10/2006] [Indexed: 11/16/2022]
Abstract
Cocaine is a powerful and addictive stimulant whose abuse remains a prevalent health and societal crisis. Unfortunately, no pharmacological therapies exist and therefore alternative protein-based therapies have been examined. One such approach is immunopharmacotherapy, wherein antibodies are utilized to either bind or hydrolyze cocaine thereby blocking it from exerting its euphoric effect. Towards this end, antibodies capable of binding and hydrolyzing cocaine were identified by phage display from a biased single chain antibody library generated from the spleens of mice previously immunized with a cocaine phosphonate transition state analog hapten. Two classes of antibodies emerged based on sequence homology and mode of action. Alanine scanning mutagenesis and kinetic analysis revealed that residues H97, H99, and L96 are crucial for antibodies 3F5 and 3H9 to accelerate the hydrolysis of cocaine. Antibodies 3F1 through 3F4, which are similar to our previously identified 3A6 class of antibodies, catalyze hydrolysis through transition state stabilization by tyrosine or histidine residues H50 and L94. Mutation of either one or both tyrosine residues to histidine conferred hydrolytic activity on previously inactive antibody 3F4. Mutational analysis of residue H50 of antibody 3F3 resulted in a glutamine mutant with a rate enhancement three times greater than wild-type. A double mutant, containing glutamineH50 and lysineH52, showed a tenfold rate enhancement over wild-type. These results indicate the power of initial selection of catalytic antibodies from a biased antibody library in both rapid generation and screening of mutants for improved catalysis.
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Affiliation(s)
| | | | | | | | | | - Kim D. Janda
- *Corresponding author, Email addresses of the corresponding authors:
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16
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Norman AB, Tabet MR, Norman MK, Buesing WR, Pesce AJ, Ball WJ. A chimeric human/murine anticocaine monoclonal antibody inhibits the distribution of cocaine to the brain in mice. J Pharmacol Exp Ther 2006; 320:145-53. [PMID: 17023573 DOI: 10.1124/jpet.106.111781] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The predominantly human sequence, high-affinity anticocaine monoclonal antibody (mAb) 2E2 was cleared slowly from mouse blood by a first-order process with an elimination t(1/2) of 8.1 days. Infused 2E2 also produced a dramatic dose-dependent increase in plasma cocaine concentrations and a concomitant decrease in the brain cocaine concentrations produced by an i.v. injection of cocaine HCl (0.56 mg/kg). At the highest dose of 2E2 tested (3:1, mAb/drug), cocaine was not detectable in the brain. Pharmacokinetic studies showed that the normal disappearance of cocaine from plasma was described by a two-compartment pharmacokinetic model with distribution t(1/2alpha) and terminal elimination t(1/2beta) values of 1.9 and 26.1 min, respectively. In the presence of an equimolar dose of mAb 2E2, there was a 26-fold increase in the area under the plasma cocaine concentration-time curve (AUC) relative to the AUC in the absence of 2E2. Consequently, 2E2 decreased the volume of distribution of cocaine from 6.0 to 0.20 l/kg, which approximated that of 2E2 (0.28 l/kg). However, cocaine was still rapidly cleared from plasma, and its elimination was now described by a single-compartment model with an elimination t(1/2) of 17 min. Importantly, 2E2 also produced a 4.5-fold (78%) decrease in the cocaine AUC in the brain. Therefore, the effect of 2E2 on plasma and brain cocaine concentrations was predominantly caused by a change in the distribution of cocaine with negligible effects on its rate of clearance. These data support the concept of immunotherapy for drug abuse.
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Affiliation(s)
- Andrew B Norman
- Division of Neuroscience, Department of Psychiatry, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0559, USA.
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17
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Takahashi-Ando N, Shimazaki K, Kakinuma H, Fujii I, Nishi Y. Molecular mechanisms of improvement of hydrolytic antibody 6D9 by site-directed mutagenesis. J Biochem 2006; 140:509-15. [PMID: 16921165 DOI: 10.1093/jb/mvj179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed a series of site-directed mutagenesis experiments of catalytic antibody, 6D9, which hydrolyzes a prodrug of chloramphenicol, based on our previous directed evolution study [Takahashi et al. (2001) Nat. Biotechnol. 19, 563-567]. Since we previously found that the variants with a mutation of Ser(L27e)Tyr afforded a one order of magnitude increase in catalytic rate, we created a site-directed mutant containing this mutation. The resulting mutant, 6D9-Ser(L27e)Tyr, had 6.5-fold higher k(cat)/k(uncat) and 9.8-fold higher k(cat)/K(m) than wild-type 6D9. We also created 6D9-Thr(L27a)Pro, since this mutation occurred frequently in the previous directed evolution, and it had 2.1-fold higher k(cat)/k(uncat) and k(cat)/K(m) than 6D9. Kinetic and computational analyses suggest that Tyr at L27e contributes to transition-state stabilization, while Pro at L27a does not interact with the transition-state structure directly, but obviously contributes to enhanced catalytic activity. Including double mutants that combined favourable substitutions, we created seven site-directed mutants. However, none of them had higher catalytic activities than some of highly improved variants obtained in the previous directed evolution. The present study gives direct evidence that not only a specific amino acid residue which obviously contributes to transition-state stabilization, but also a group of amino acid residues working in concert is important for efficient catalysis of a given transformation.
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Affiliation(s)
- Naoko Takahashi-Ando
- Laboratory of Life Science & Biomolecular Engineering, Japan Tobacco, Inc. 6-2, Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512.
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18
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Zhu X, Dickerson TJ, Rogers CJ, Kaufmann GF, Mee JM, McKenzie KM, Janda KD, Wilson IA. Complete reaction cycle of a cocaine catalytic antibody at atomic resolution. Structure 2006; 14:205-16. [PMID: 16472740 DOI: 10.1016/j.str.2005.10.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 09/27/2005] [Accepted: 10/04/2005] [Indexed: 11/30/2022]
Abstract
Antibody 7A1 hydrolyzes cocaine to produce nonpsychoactive metabolites ecgonine methyl ester and benzoic acid. Crystal structures of 7A1 Fab' and six complexes with substrate cocaine, the transition state analog, products ecgonine methyl ester and benzoic acid together and individually, as well as heptaethylene glycol have been analyzed at 1.5-2.3 angstroms resolution. Here, we present snapshots of the complete cycle of the cocaine hydrolytic reaction at atomic resolution. Significant structural rearrangements occur along the reaction pathway, but they are generally limited to the binding site, including the ligands themselves. Several interacting side chains either change their rotamers or alter their mobility to accommodate the different reaction steps. CDR loop movements (up to 2.3 angstroms) and substantial side chain rearrangements (up to 9 angstroms) alter the shape and size (approximately 320-500 angstroms3) of the antibody active site from "open" to "closed" to "open" for the substrate, transition state, and product states, respectively.
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Affiliation(s)
- Xueyong Zhu
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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