1
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Wang G, Moitessier N, Mittermaier AK. Computational and biophysical methods for the discovery and optimization of covalent drugs. Chem Commun (Camb) 2023; 59:10866-10882. [PMID: 37609777 DOI: 10.1039/d3cc03285j] [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: 08/24/2023]
Abstract
Drugs that act by covalently attaching to their targets have been used to treat human diseases for over a hundred years. However, the deliberate design of covalent drugs was discouraged due to concerns of toxicity and off-target effects. Recent successes in covalent drug discovery have sparked fresh interest in this field. New screening and testing methods aimed at covalent inhibitors can play pivotal roles in facilitating the discovery process. This feature article focuses on computational and biophysical advances originating from our labs over the past decade and how these approaches have contributed to the design of prolyl oligopeptidase (POP) and SARS-CoV-2 3CLpro covalent inhibitors.
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Affiliation(s)
- Guanyu Wang
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.
| | - Nicolas Moitessier
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.
| | - Anthony K Mittermaier
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.
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2
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Aromatic Schiff bases confer inhibitory efficacy against New Delhi metallo-β-lactamase-1 (NDM-1). Bioorg Chem 2022; 126:105910. [PMID: 35653899 DOI: 10.1016/j.bioorg.2022.105910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 05/10/2022] [Accepted: 05/23/2022] [Indexed: 12/24/2022]
Abstract
The irregular use of antibiotics has created a natural selection pressure for bacteria to adapt resistance. Bacterial resistance caused by metallo-β-lactamases (MβLs) has been the most prevalent in terms of posing a threat to human health. The New Delhi metallo-β-lactamase-1 (NDM-1) has been shown to be capable of hydrolyzing almost all β-lactams. In this work, eight aromatic Schiff bases 1-8 were prepared and identified by enzyme kinetic assays to be the potent inhibitors of NDM-1 (except 4). These molecules exhibited a more than 95 % inhibition, and an IC50 value in the range of 0.13-19 μM on the target enzyme, and 3 was found to be the most effective inhibitor (IC50 = 130 nM). Analysis of structure-activity relationship revealed that the o-hydroxy phenyl improved the inhibitory activity of Schiff bases on NDM-1. The inhibition mode assays including isothermal titration calorimetry (ITC) disclosed that both compounds 3 and 5 exhibited a reversibly mixed inhibition on NDM-1, with a Ki value of 1.9 and 10.8 μM, respectively. Antibacterial activity tests indicated that a dose of 64 μg·mL-1 Schiff bases resulted in 2-128-fold reduction in MICs of cefazolin on E. coli producing NDM-1 (except 4). Cytotoxicity assays showed that both Schiff bases 3 and 5 have low cytotoxicity on the mouse fibroblast (L929) cells at a concentration of up to 400 μM. Docking studies suggested that the hydroxyl group interacts with Gln123 and Glu152 of NDM-1, and the amino groups interact with the backbone amide groups of Glu152 and Asp223. This study provided a novel scaffold for the development of NDM-1 inhibitors.
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3
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Rindfleisch S, Krull M, Uranga J, Schmidt T, Rabe von Pappenheim F, Kirck LL, Balouri A, Schneider T, Chari A, Kluger R, Bourenkov G, Diederichsen U, Mata RA, Tittmann K. Ground-state destabilization by electrostatic repulsion is not a driving force in orotidine-5′-monophosphate decarboxylase catalysis. Nat Catal 2022. [DOI: 10.1038/s41929-022-00771-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Negrya SD, Efremenkova OV, Solyev PN, Chekhov VO, Ivanov MA, Sumarukova IG, Karpenko IL, Kochetkov SN, Alexandrova LA. Novel 5-substituted derivatives of 2’-deoxy-6-azauridine with antibacterial activity. J Antibiot (Tokyo) 2019; 72:535-544. [DOI: 10.1038/s41429-019-0158-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/15/2019] [Accepted: 01/27/2019] [Indexed: 01/13/2023]
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5
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Zhang Y, Lei J, He Y, Yang J, Wang W, Wasey A, Xu J, Lin Y, Fan H, Jing G, Zhang C, Jin Y. Label‐Free Visualization of Carbapenemase Activity in Living Bacteria. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ye Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jin‐E Lei
- The First Affiliated Hospital of Xi'an Jiaotong University Xi'an Jiatong University Xi'an 710061 P. R. China
| | - Yuan He
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jianhua Yang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Wenjing Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Abdul Wasey
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jiru Xu
- The First Affiliated Hospital of Xi'an Jiaotong University Xi'an Jiatong University Xi'an 710061 P. R. China
| | - Yue Lin
- Scion New Zealand Forest Research Institute) Rotorua 3010 New Zealand
| | - Haiming Fan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Guangyin Jing
- College of Physics Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Ce Zhang
- College of Physics Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Yi Jin
- School of Chemistry Cardiff University Cardiff CF10 3AT UK
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6
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Zhang YJ, Wang WM, Oelschlaeger P, Chen C, Lei JE, Lv M, Yang KW. Real-Time Monitoring of NDM-1 Activity in Live Bacterial Cells by Isothermal Titration Calorimetry: A New Approach To Measure Inhibition of Antibiotic-Resistant Bacteria. ACS Infect Dis 2018; 4:1671-1678. [PMID: 30383355 DOI: 10.1021/acsinfecdis.8b00147] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The "superbug" infection caused by New Delhi metallo-β-lactamase (NDM-1) has become an emerging threat. Monitoring NDM-1 has proven challenging due to its shuttling between pathogenic bacteria. Here, we report an isothermal titration calorimetry (ITC) method that can monitor activity and inhibition of NDM-1 in live bacterial cells in real time. This method has been exemplified by monitoring of the activity and inhibition of the target enzyme and evaluating the breakdown of antibiotics by pathogenic bacteria expressing β-lactamases. Cell-based studies demonstrate that the NDM-1 expressed in bacterial cells was inhibited by four known inhibitors ethylene diamine tetraacetic acid (EDTA), d-captopril, ebselen and azolylthioacetamide with fifty percent inhibitory concentration (IC50) values of 3.8, 48, 0.55, and 17.5 μM, respectively, which are in good agreement with the data from inhibition kinetics using UV-vis and NMR spectroscopy in vivo. This approach could be applied to screen and evaluate small molecule inhibitors of metallo-β-lactamases (MβLs) in whole cells or to identify drug resistant bacteria.
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Affiliation(s)
- Yue-Juan Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Wen-Ming Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Peter Oelschlaeger
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 East Second Street, Pomona, California 91766, United States
| | - Cheng Chen
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Jin-E Lei
- The First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an, Shaanxi 710061, P.R. China
| | - Miao Lv
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Ke-Wu Yang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
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7
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Zhang Y, Lei J, He Y, Yang J, Wang W, Wasey A, Xu J, Lin Y, Fan H, Jing G, Zhang C, Jin Y. Label‐Free Visualization of Carbapenemase Activity in Living Bacteria. Angew Chem Int Ed Engl 2018; 57:17120-17124. [DOI: 10.1002/anie.201810834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/19/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Ye Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jin‐E Lei
- The First Affiliated Hospital of Xi'an Jiaotong University Xi'an Jiatong University Xi'an 710061 P. R. China
| | - Yuan He
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jianhua Yang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Wenjing Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Abdul Wasey
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Jiru Xu
- The First Affiliated Hospital of Xi'an Jiaotong University Xi'an Jiatong University Xi'an 710061 P. R. China
| | - Yue Lin
- Scion New Zealand Forest Research Institute) Rotorua 3010 New Zealand
| | - Haiming Fan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Guangyin Jing
- College of Physics Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Ce Zhang
- College of Physics Northwest University 1 Xue Fu Avenue Xi'an 710127 P. R. China
| | - Yi Jin
- School of Chemistry Cardiff University Cardiff CF10 3AT UK
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8
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Di Trani JM, Moitessier N, Mittermaier AK. Complete Kinetic Characterization of Enzyme Inhibition in a Single Isothermal Titration Calorimetric Experiment. Anal Chem 2018; 90:8430-8435. [DOI: 10.1021/acs.analchem.8b00993] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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9
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Slusarczyk M, Ferla S, Brancale A, McGuigan C. Synthesis and biological evaluation of 6-substituted-5-fluorouridine ProTides. Bioorg Med Chem 2017; 26:551-565. [PMID: 29277307 DOI: 10.1016/j.bmc.2017.11.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 11/29/2022]
Abstract
A new family of thirteen phosphoramidate prodrugs (ProTides) of different 6-substituted-5-fluorouridine nucleoside analogues were synthesized and evaluated as potential anticancer agents. In addition, antiviral activity against Chikungunya (CHIKV) virus was evaluated using a cytopathic effect inhibition assay. Although a carboxypeptidase Y assay supported a putative mechanism of activation of ProTides built on 5-fluorouridine with such C6-modifications, the Hint docking studies revealed a compromised substrate-activity for the Hint phosphoramidase-type enzyme that is likely responsible for phosphoramidate bioactivation through P-N bond cleavage and free nucleoside 5'-monophosphate delivery. Our observations may support and explain to some extent the poor in vitro biological activity generally demonstrated by the series of 6-substituted-5-fluorouridine phosphoramidates (ProTides) and will be of guidance for the design of novel phosphoramidate prodrugs.
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Affiliation(s)
- Magdalena Slusarczyk
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, King Edward VII Avenue, Cardiff CF10 3NB, UK.
| | - Salvatore Ferla
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, King Edward VII Avenue, Cardiff CF10 3NB, UK
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, King Edward VII Avenue, Cardiff CF10 3NB, UK
| | - Christopher McGuigan
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, King Edward VII Avenue, Cardiff CF10 3NB, UK
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10
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Di Trani JM, Moitessier N, Mittermaier AK. Measuring Rapid Time-Scale Reaction Kinetics Using Isothermal Titration Calorimetry. Anal Chem 2017; 89:7022-7030. [PMID: 28590118 DOI: 10.1021/acs.analchem.7b00693] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Isothermal titration calorimetry (ITC) is a powerful tool for acquiring both thermodynamic and kinetic data for biological interactions including molecular recognition and enzymatic catalysis. ITC-based kinetics measurements typically focus on reactions taking place over long time scales (tens of minutes or hours) in order to avoid complications due to the finite length of time needed detect heat flow in the calorimeter cell. While progress has been made toward analyzing more rapid reaction kinetics by ITC, the capabilities and limitations of this approach have not been thoroughly tested to date. Here, we report that the time resolution of commercial instruments is on the order of 0.2 s or less. We successfully performed rapid ITC kinetics assays with durations of just tens of seconds using the enzyme trypsin. This is substantially shorter than previous ITC enzyme measurements. However, we noticed that for short reaction durations, standard assumptions regarding the ITC instrument response led to significant deviations between calculated and measured ITC peak shapes. To address this issue, we developed an ITC empirical response model (ITC-ERM) that quantitatively reproduces ITC peak shapes for all reaction durations. Applying the ITC-ERM approach to another enzyme (prolyl oligopeptidase), we unexpectedly discovered non-Michaelis-Menten kinetics in short time-scale measurements that are absent in more typical long time-scale experiments and are obscured in short time-scale experiments when standard assumptions regarding the instrument response are made. This highlights the potential of ITC measurements of rapid time scale kinetics in conjunction with the ITC-ERM approach to shed new light on biological dynamics.
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Affiliation(s)
- Justin M Di Trani
- Department of Chemistry, McGill University , H3A 0B8 Montreal, Canada
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11
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Chang YN, Xiang Y, Zhang YJ, Wang WM, Chen C, Oelschlaeger P, Yang KW. Carbamylmethyl Mercaptoacetate Thioether: A Novel Scaffold for the Development of L1 Metallo-β-lactamase Inhibitors. ACS Med Chem Lett 2017; 8:527-532. [PMID: 28523105 DOI: 10.1021/acsmedchemlett.7b00058] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/24/2017] [Indexed: 12/30/2022] Open
Abstract
Given the clinical importance of metallo-β-lactamases (MβLs), a new scaffold, N-substituted carbamylmethyl mercaptoacetate thioether, was constructed. The obtained molecules 1-16 inhibited MβLs from all three subclasses, but preferentially L1 from subclass B3. Compound 9 with a p-carboxyphenyl substituent exhibited the broadest spectrum with at least 70% inhibition of enzymes from all subclasses at 100 μM, while compound 5 with a p-methylphenyl substituent was the most potent inhibitor of any individual enzyme, with 97% inhibition at 100 μM and an IC50 value of 0.41 μM against L1. Isothermal titration calorimetry assays corroborate findings from UV-vis spectrophotometric assays that the inhibition of L1 by 5 is dose-dependent. Docking studies suggest that the carboxyl group, the sulfide atom, and the carbonyl group of the carbamyl coordinate Zn2 in a chelating fashion. Using E. coli cells expressing L1, 6 and 8 were able to decrease cefazolin minimum inhibitory concentration 8-fold.
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Affiliation(s)
- Ya-Nan Chang
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Yang Xiang
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Yue-Juan Zhang
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Wen-Ming Wang
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Cheng Chen
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Peter Oelschlaeger
- Department
of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 East Second Street, Pomona, California 91766, United States
| | - Ke-Wu Yang
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, Chemical Biology Innovation Laboratory,
College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
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12
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Blackburn DJ, Kent GT, Wu W. Regiospecific synthesis of 6-halouridine derivatives: An effective method for coupling sterically hindered pyrimidine bases to ribose. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.02.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Klimenko K, Marcou G, Horvath D, Varnek A. Chemical Space Mapping and Structure-Activity Analysis of the ChEMBL Antiviral Compound Set. J Chem Inf Model 2016; 56:1438-54. [PMID: 27410486 DOI: 10.1021/acs.jcim.6b00192] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Curation, standardization and data fusion of the antiviral information present in the ChEMBL public database led to the definition of a robust data set, providing an association of antiviral compounds to seven broadly defined antiviral activity classes. Generative topographic mapping (GTM) subjected to evolutionary tuning was then used to produce maps of the antiviral chemical space, providing an optimal separation of compound families associated with the different antiviral classes. The ability to pinpoint the specific spots occupied (responsibility patterns) on a map by various classes of antiviral compounds opened the way for a GTM-supported search for privileged structural motifs, typical for each antiviral class. The privileged locations of antiviral classes were analyzed in order to highlight underlying privileged common structural motifs. Unlike in classical medicinal chemistry, where privileged structures are, almost always, predefined scaffolds, privileged structural motif detection based on GTM responsibility patterns has the decisive advantage of being able to automatically capture the nature ("resolution detail"-scaffold, detailed substructure, pharmacophore pattern, etc.) of the relevant structural motifs. Responsibility patterns were found to represent underlying structural motifs of various natures-from very fuzzy (groups of various "interchangeable" similar scaffolds), to the classical scenario in medicinal chemistry (underlying motif actually being the scaffold), to very precisely defined motifs (specifically substituted scaffolds).
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Affiliation(s)
- Kyrylo Klimenko
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France.,Department on Molecular Structure and Chemoinformatics, A.V. Bogatsky Physico-Chemical Institute of NAS of Ukraine , Lyustdorfskaya doroga, 86, Odessa 65080, Ukraine
| | - Gilles Marcou
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
| | - Dragos Horvath
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
| | - Alexandre Varnek
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
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14
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Zhang Q, Mi Z, Huang Y, Ma L, Ding J, Wang J, Zhang Y, Chen Y, Zhou J, Guo F, Li X, Cen S. 2-thio-6-azauridine inhibits Vpu mediated BST-2 degradation. Retrovirology 2016; 13:13. [PMID: 26935098 PMCID: PMC4776379 DOI: 10.1186/s12977-016-0247-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/25/2016] [Indexed: 12/31/2022] Open
Abstract
Backgroud
BST-2 is an interferon-induced host restriction factor that inhibits the release of diverse mammalian enveloped viruses from infected cells by physically trapping the newly formed virions onto the host cell surface. Human Immunodeficiency Virus-1 (HIV-1) encodes an accessory protein Vpu that antagonizes BST-2 by down-regulating BST-2 from the cell surface. Results Using a cell-based ELISA screening system, we have discovered a lead compound, 2-thio-6-azauridine, that restores cell surface BST-2 level in the presence of Vpu. This compound has no effect on the expression of BST-2 and Vpu, but inhibits Vpu-mediated BST-2 down-regulation and exerts no effect on Vpu-induced down-regulation of CD4 or KSHV K5 protein induced BST-2 down-regulation. 2-thio-6-azauridine suppresses HIV-1 production in a BST-2-dependent manner. Further results indicate that 2-thio-6-azauridine does not interrupt the interaction of BST-2 with Vpu and β-TrCP2, but decreases BST-2 ubiquitination. Conclusion Our study demonstrates the feasibility of using small molecules to target Vpu function and sensitize wild type HIV-1 to BST-2-mediated host restriction. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0247-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Quan Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Zeyun Mi
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China. .,Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin, China.
| | - Yuming Huang
- Beijing Ditan Hospital, Capital Medical University, Beijing, China.
| | - Ling Ma
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jiwei Ding
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jing Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Yongxin Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Yang Chen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Jinming Zhou
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Fei Guo
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Xiaoyu Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
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15
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Active-Site Plasticity Is Essential to Carbapenem Hydrolysis by OXA-58 Class D β-Lactamase of Acinetobacter baumannii. Antimicrob Agents Chemother 2015; 60:75-86. [PMID: 26459904 DOI: 10.1128/aac.01393-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 10/03/2015] [Indexed: 01/09/2023] Open
Abstract
Carbapenem-hydrolyzing class D β-lactamases (CHDLs) are a subgroup of class D β-lactamases, which are enzymes that hydrolyze β-lactams. They have attracted interest due to the emergence of multidrug-resistant Acinetobacter baumannii, which is not responsive to treatment with carbapenems, the usual antibiotics of choice for this bacterium. Unlike other class D β-lactamases, these enzymes efficiently hydrolyze carbapenem antibiotics. To explore the structural requirements for the catalysis of carbapenems by these enzymes, we determined the crystal structure of the OXA-58 CHDL of A. baumannii following acylation of its active-site serine by a 6α-hydroxymethyl penicillin derivative that is a structural mimetic for a carbapenem. In addition, several point mutation variants of the active site of OXA-58, as identified by the crystal structure analysis, were characterized kinetically. These combined studies confirm the mechanistic relevance of a hydrophobic bridge formed over the active site. This structural feature is suggested to stabilize the hydrolysis-productive acyl-enzyme species formed from the carbapenem substrates of this enzyme. Furthermore, our structural studies provide strong evidence that the hydroxyethyl group of carbapenems samples different orientations in the active sites of CHDLs, and the optimum orientation for catalysis depends on the topology of the active site allowing proper closure of the active site. We propose that CHDLs use the plasticity of the active site to drive the mechanism of carbapenem hydrolysis toward efficiency.
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16
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Fujihashi M, Mnpotra JS, Mishra RK, Pai EF, Kotra LP. Orotidine Monophosphate Decarboxylase--A Fascinating Workhorse Enzyme with Therapeutic Potential. J Genet Genomics 2015; 42:221-34. [PMID: 26059770 DOI: 10.1016/j.jgg.2015.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 10/23/2022]
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) is known as one of the most proficient enzymes. The enzyme catalyzes the last reaction step of the de novo pyrimidine biosynthesis, the conversion from orotidine 5'-monophosphate (OMP) to uridine 5'-monophosphate. The enzyme is found in all three domains of life, Bacteria, Eukarya and Archaea. Multiple sequence alignment of 750 putative ODCase sequences resulted in five distinct groups. While the universally conserved DxKxxDx motif is present in all the groups, depending on the groups, several characteristic motifs and residues can be identified. Over 200 crystal structures of ODCases have been determined so far. The structures, together with biochemical assays and computational studies, elucidated that ODCase utilized both transition state stabilization and substrate distortion to accelerate the decarboxylation of its natural substrate. Stabilization of the vinyl anion intermediate by a conserved lysine residue at the catalytic site is considered the largest contributing factor to catalysis, while bending of the carboxyl group from the plane of the aromatic pyrimidine ring of OMP accounts for substrate distortion. A number of crystal structures of ODCases complexed with potential drug candidate molecules have also been determined, including with 6-iodo-uridine, a potential antimalarial agent.
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Affiliation(s)
- Masahiro Fujihashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Jagjeet S Mnpotra
- Department of Chemistry & Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC, 27412, USA
| | - Ram Kumar Mishra
- Center for Molecular Design and Preformulations, and Toronto General Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Emil F Pai
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada; Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Lakshmi P Kotra
- Center for Molecular Design and Preformulations, and Toronto General Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada; Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada.
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Jamshidi S, Jalili S, Rafii-Tabar H. Study of orotidine 5'-monophosphate decarboxylase in complex with the top three OMP, BMP, and PMP ligands by molecular dynamics simulation. J Biomol Struct Dyn 2014; 33:404-17. [PMID: 24559040 DOI: 10.1080/07391102.2014.881303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Catalytic mechanism of orotidine 5'-monophosphate decarboxylase (OMPDC), one of the nature most proficient enzymes which provides large rate enhancement, has not been fully understood yet. A series of 30 ns molecular dynamics (MD) simulations were run on X-ray structure of the OMPDC from Saccharomyces cerevisiae in its free form as well as in complex with different ligands, namely 1-(5'-phospho-D-ribofuranosyl) barbituric acid (BMP), orotidine 5'-monophosphate (OMP), and 6-phosphonouridine 5'-monophosphate (PMP). The importance of this biological system is justified both by its high rate enhancement and its potential use as a target in chemotherapy. This work focuses on comparing two physicochemical states of the enzyme (protonated and deprotonated Asp91) and three ligands (substrate OMP, inhibitor, and transition state analog BMP and substrate analog PMP). Detailed analysis of the active site geometry and its interactions is properly put in context by extensive comparison with relevant experimental works. Our overall results show that in terms of hydrogen bond occupancy, electrostatic interactions, dihedral angles, active site configuration, and movement of loops, notable differences among different complexes are observed. Comparison of the results obtained from these simulations provides some detailed structural data for the complexes, the enzyme, and the ligands, as well as useful insights into the inhibition mechanism of the OMPDC enzyme. Furthermore, these simulations are applied to clarify the ambiguous mechanism of the OMPDC enzyme, and imply that the substrate destabilization and transition state stabilization contribute to the mechanism of action of the most proficient enzyme, OMPDC.
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Affiliation(s)
- Shirin Jamshidi
- a Faculty of Medicine, Department of Medical Physics and Biomedical Engineering , Shahid Beheshti University of Medical Sciences , Evin, Tehran , Iran
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Abstract
ODCase is a highly proficient enzyme responsible for the decarboxylation of orotidine monophosphate to generate uridine monophosphate. ODCase has attracted early attention due to its interesting mechanism of catalysis. In order to exploit therapeutic advantages due to the inhibition of ODCase, one must have selective inhibitors of this enzyme from the pathogen, or a dysregulated molecular mechanism involving ODCase. ODCase inhibitors have potential applications as anticancer agents, antiviral agents, antimalarial agents and potentially act against other parasitic diseases. A variety of C6-substituted uridine monophosphate derivatives have shown excellent inhibition of ODCase. 6-iodouridine is a potent inhibitor of the malaria parasite, and its monophosphate form covalently inhibits ODCase. A variety of inhibitors of ODCase with potential applications as therapeutic agents are discussed in this review.
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Fujihashi M, Ishida T, Kuroda S, Kotra LP, Pai EF, Miki K. Substrate distortion contributes to the catalysis of orotidine 5'-monophosphate decarboxylase. J Am Chem Soc 2013; 135:17432-43. [PMID: 24151964 PMCID: PMC3949427 DOI: 10.1021/ja408197k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) accelerates the decarboxylation of orotidine 5'-monophosphate (OMP) to uridine 5'-monophosphate (UMP) by 17 orders of magnitude. Eight new crystal structures with ligand analogues combined with computational analyses of the enzyme's short-lived intermediates and the intrinsic electronic energies to distort the substrate and other ligands improve our understanding of the still controversially discussed reaction mechanism. In their respective complexes, 6-methyl-UMP displays significant distortion of its methyl substituent bond, 6-amino-UMP shows the competition between the K72 and C6 substituents for a position close to D70, and the methyl and ethyl esters of OMP both induce rotation of the carboxylate group substituent out of the plane of the pyrimidine ring. Molecular dynamics and quantum mechanics/molecular mechanics computations of the enzyme-substrate complex also show the bond between the carboxylate group and the pyrimidine ring to be distorted, with the distortion contributing a 10-15% decrease of the ΔΔG(⧧) value. These results are consistent with ODCase using both substrate distortion and transition-state stabilization, primarily exerted by K72, in its catalysis of the OMP decarboxylation reaction.
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Affiliation(s)
- Masahiro Fujihashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Toyokazu Ishida
- Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan
| | - Shingo Kuroda
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Lakshmi P. Kotra
- Center for Molecular Design and Preformulations and Division of Cell & Molecular Biology, Toronto General Research Institute/University Health Network, Toronto, ON, Canada M5G 1L7
- Departments of Pharmaceutical Sciences and Chemistry, McLaughlin Center for Molecular Medicine, University of Toronto, Canada M5S 3M2
| | - Emil F. Pai
- Center for Molecular Design and Preformulations and Division of Cell & Molecular Biology, Toronto General Research Institute/University Health Network, Toronto, ON, Canada M5G 1L7
- The Campbell Family Cancer Research Institute, Ontario Cancer Institute/University Health Network & Departments of Biochemistry, Medical Biophysics, and Molecular Genetics, University of Toronto, Toronto, ON, Canada M5G 1L7
| | - Kunio Miki
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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Fujihashi M, Mito K, Pai EF, Miki K. Atomic resolution structure of the orotidine 5'-monophosphate decarboxylase product complex combined with surface plasmon resonance analysis: implications for the catalytic mechanism. J Biol Chem 2013; 288:9011-6. [PMID: 23395822 DOI: 10.1074/jbc.m112.427252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) accelerates the decarboxylation of its substrate by 17 orders of magnitude. One argument brought forward against steric/electrostatic repulsion causing substrate distortion at the carboxylate substituent as part of the catalysis has been the weak binding affinity of the decarboxylated product (UMP). The crystal structure of the UMP complex of ODCase at atomic resolution (1.03 Å) shows steric competition between the product UMP and the side chain of a catalytic lysine residue. Surface plasmon resonance analysis indicates that UMP binds 5 orders of magnitude more tightly to a mutant in which the interfering side chain has been removed than to wild-type ODCase. These results explain the low affinity of UMP and counter a seemingly very strong argument against a contribution of substrate distortion to the catalytic reaction mechanism of ODCase.
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Affiliation(s)
- Masahiro Fujihashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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Purohit MK, Poduch E, Wei LW, Crandall IE, To T, Kain KC, Pai EF, Kotra LP. Novel cytidine-based orotidine-5'-monophosphate decarboxylase inhibitors with an unusual twist. J Med Chem 2012; 55:9988-97. [PMID: 22991951 DOI: 10.1021/jm301176r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Orotidine-5'-monophosphate decarboxylase (ODCase) is an interesting enzyme with an unusual catalytic activity and a potential drug target in Plasmodium falciparum, which causes malaria. ODCase has been shown to exhibit unusual and interesting interactions with a variety of nucleotide ligands. Cytidine-5'-monophosphate (CMP) is a poor ligand of ODCase, and CMP binds to the active site of ODCase with an unusual orientation and conformation. We designed N3- and N4-modified CMP derivatives as novel ligands to ODCase. These novel CMP derivatives and their corresponding nucleosides were evaluated against Plasmodium falciparum ODCase and parasitic cultures, respectively. These derivatives exhibited improved inhibition of the enzyme catalytic activity, displayed interesting binding conformations and unusual molecular rearrangements of the ligands. These findings with the modified CMP nucleotides underscored the potential of transformation of poor ligands to ODCase into novel inhibitors of this drug target.
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Affiliation(s)
- Meena K Purohit
- Center for Molecular Design and Preformulations, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 1L7, Canada
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22
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5-azacytosine compounds in medicinal chemistry: current stage and future perspectives. Future Med Chem 2012; 4:991-1005. [DOI: 10.4155/fmc.12.36] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This review summarizes the basic milestones of the research of 5-azacytosine nucleosides chronologically from their discovery and anticancer activity identification, through to subsequent unveiling of their mechanism of action based on DNA hypomethylation and tumor-suppressor gene reactivation, to the final US FDA approval of 5-azacytidine (Vidaza®) and 2´-deoxy-5-azacytidine (Dacogen®) for the treatment of myelodysplastic syndromes. 5,6-dihydro-2´-deoxy-5-azacytidine, a compound with anti-HIV activity through lethal mutagenesis, representing a unique mechanism of action among existing anti-retroviral drugs, is discussed together with quite recent discovery of its so far unexpected hypomethylation activity. Special attention is paid to 5-azacytosine acyclic nucleoside analogues and phosphonomethyl derivatives with the emphasis on the new potent anti-DNA virus agent (S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]-5-azacytosine and its prodrug forms. Considering the potential pharmaceutical applications, 5-azacytosine and 5,6-dihydro-5-azacytosine appear to be so far the most effective cytosine mimics for the design of novel antiviral and anti-tumor drug candidates.
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23
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Recht MI, Sridhar V, Badger J, Hernandez L, Chie-Leon B, Nienaber V, Torres FE. Fragment-based screening for inhibitors of PDE4A using enthalpy arrays and X-ray crystallography. ACTA ACUST UNITED AC 2012; 17:469-80. [PMID: 22223051 DOI: 10.1177/1087057111430987] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fragment-based screening has typically relied on X-ray or nuclear magnetic resonance methods to identify low-affinity ligands that bind to therapeutic targets. These techniques are expensive in terms of material and time, so it useful to have a higher throughput method to reliably prescreen a fragment library to identify a subset of compounds for structural analysis. Calorimetry provides a label-free method to assay binding and enzymatic activity that is unaffected by the spectroscopic properties of the sample. Conventional microcalorimetry is hampered by requiring large quantities of reagents and long measurement times. Nanocalorimeters can overcome these limitations of conventional isothermal titration calorimetry. Here we have used enthalpy arrays, which are arrays of nanocalorimeters, to perform an enzyme activity-based fragment screen for competitive inhibitors of phosphodiesterase 4A (PDE4A). Several inhibitors with K ( I ) <2 mM were identified and moved to X-ray crystallization trials. Although the co-crystals did not yield high-resolution data, evidence of binding was observed, and the chemical structures of the hits were consistent with motifs of known PDE4 inhibitors. This study shows how array calorimetry can be used as a prescreening method for fragment-based lead discovery with enzyme targets and provides a list of candidate fragments for inhibition of PDE4A.
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Yuan J, Cardenas AM, Gilbert HF, Palzkill T. Determination of the amino acid sequence requirements for catalysis by the highly proficient orotidine monophosphate decarboxylase. Protein Sci 2011; 20:1891-906. [PMID: 21898650 DOI: 10.1002/pro.728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 08/15/2011] [Accepted: 08/18/2011] [Indexed: 12/12/2022]
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) catalyzes the decarboxylation of orotidine 5'-monophosphate to uridine 5'-monophosphate during pyrimidine nucleotide biosynthesis. This enzyme is one of the most proficient known, exhibiting a rate enhancement of over 17 orders of magnitude over the uncatalyzed rate. An interesting question is whether the high proficiency of ODCase is associated with a highly optimized sequence of active site residues. This question was addressed by randomizing 24 residue positions in and around the active site of the E. coli ODCase (pyrF) by site-directed mutagenesis. The libraries of mutants were selected for function from a multicopy plasmid or by single-copy replacement at the pyrF locus on the E. coli chromosome. Stringent sequence requirements for function were found for the mutants expressed from the chromosomal pyrF locus. Six positions were not tolerant of substitutions and several others accepted very limited substitutions. In contrast, all positions could be substituted to some extent when the library mutants were expressed from a multicopy plasmid. For the conserved quartet of charged residues Lys44-Asp71-Lys73-Asp76, a cysteine substitution was found to provide function at positions 71 and 76. A lower pK(a) for both cysteine mutants supports a mechanism whereby the thiolate group of cysteine substitutes for the negatively charged aspartate side chain. The partial function mutants such as D71C and D76C exhibit reduced catalytic efficiency relative to wild type but nevertheless provide a rate enhancement of 15 orders of magnitude over the uncatalyzed rate indicating the catalytic proficiency of the enzyme is robust and tolerant of mutation.
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Affiliation(s)
- Ji Yuan
- Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030, USA
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25
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Verma V, Testero SA, Amini K, Wei W, Liu J, Balachandran N, Monoharan T, Stynes S, Kotra LP, Golemi-Kotra D. Hydrolytic mechanism of OXA-58 enzyme, a carbapenem-hydrolyzing class D β-lactamase from Acinetobacter baumannii. J Biol Chem 2011; 286:37292-303. [PMID: 21880707 DOI: 10.1074/jbc.m111.280115] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carbapenem-hydrolyzing class D β-lactamases (CHDLs) represent an emerging antibiotic resistance mechanism encountered among the most opportunistic Gram-negative bacterial pathogens. We report here the substrate kinetics and mechanistic characterization of a prominent CHDL, the OXA-58 enzyme, from Acinetobacter baumannii. OXA-58 uses a carbamylated lysine to activate the nucleophilic serine used for β-lactam hydrolysis. The deacylating water molecule approaches the acyl-enzyme species, anchored at this serine (Ser-83), from the α-face. Our data show that OXA-58 retains the catalytic machinery found in class D β-lactamases, of which OXA-10 is representative. Comparison of the homology model of OXA-58 and the recently solved crystal structures of OXA-24 and OXA-48 with the OXA-10 crystal structure suggests that these CHDLs have evolved the ability to hydrolyze imipenem, an important carbapenem in clinical use, by subtle structural changes in the active site. These changes may contribute to tighter binding of imipenem to the active site and removal of steric hindrances from the path of the deacylating water molecule.
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Affiliation(s)
- Vidhu Verma
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
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26
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Lin JB, He JL, Shih YC, Chien TC. Study on the synthesis of 6-alkylaminouridines via the nucleophilic aromatic substitution reaction of 6-cyanouridine derivatives. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Almost any process in life is accompanied by heat changes which can be monitored by isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC). Both techniques are now established tools in fundamental research but over the last decade a clear tendency towards more problem-driven applications is noted. This review aims at summarizing these problem-oriented applications of microcalorimetry and the solutions both techniques can provide to problems in biotechnology. The biotechnological issues to which microcalorimetry has been successfully applied are as diverse as rational drug design, overcoming drug resistance, optimization of long-term stability of proteins, estimation of the bioavailability of drugs, control of complex pharmaceutical products or the optimization of gene delivery efficiency. The main limitation of microcalorimetry, which is the relatively large amounts of sample necessary for analysis, is less important in the biotechnology sector which frequently uses large-scale produced bulk products for analysis. The recently developed high-throughput DSC and ITC microcalorimeters will additionally reduce the labour intensity of these techniques. Due to the precision of microcalorimetric analyses and the versatility of processes which can be studied, it is expected that ITC and DSC will soon be key technologies in biotechnological research.
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Affiliation(s)
- Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/Prof. Albareda 1, 18008 Granada, Spain.
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28
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Lewis M, Meza-Avina ME, Wei L, Crandall IE, Bello AM, Poduch E, Liu Y, Paige CJ, Kain KC, Pai EF, Kotra LP. Novel interactions of fluorinated nucleotide derivatives targeting orotidine 5'-monophosphate decarboxylase. J Med Chem 2011; 54:2891-901. [PMID: 21417464 DOI: 10.1021/jm101642g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Fluorinated nucleosides and nucleotides are of considerable interest to medicinal chemists because of their antiviral, anticancer, and other biological activities. However, their direct interactions at target binding sites are not well understood. A new class of 2'-deoxy-2'-fluoro-C6-substituted uridine and UMP derivatives were synthesized and evaluated as inhibitors of orotidine 5'-monophosphate decarboxylase (ODCase or OMPDCase). These compounds were synthesized from the key intermediate, fully protected 2'-deoxy-2'-fluorouridine. Among the synthesized compounds, 2'-deoxy-2'-fluoro-6-iodo-UMP covalently inhibited human ODCase with a second-order rate constant of 0.62 ± 0.02 M(-1) s(-1). Interestingly, the 6-cyano-2'-fluoro derivative covalently interacted with ODCase defying the conventional thinking, where its ribosyl derivative undergoes transformation into BMP by ODCase. This confirms that the 2'-fluoro moiety influences the chemistry at the C6 position of the nucleotides and thus interactions in the active site of ODCase. Molecular interactions of the 2'-fluorinated nucleotides are compared to those with the 3'-fluorinated nucleotides bound to the corresponding target enzyme, and the carbohydrate moieties were shown to bind in different conformations.
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Affiliation(s)
- Melissa Lewis
- Center for Molecular Design and Preformulations and Division of Cellular and Molecular Biology, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
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Gourdain S, Petermann C, Martinez A, Harakat D, Clivio P. Synthesis and Photochemical Behavior of the Tetrazolo Tautomer of 2-Azido-4-pyrimidinone-2′-deoxyriboside. J Org Chem 2011; 76:1906-9. [DOI: 10.1021/jo102316r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stéphanie Gourdain
- Institut de Chimie Moléculaire de Reims, Université de Reims Champagne Ardenne, CNRS UMR 6229, UFR de Pharmacie, 51 rue Cognacq-Jay, 51096 Reims cedex, France
| | - Christian Petermann
- Institut de Chimie Moléculaire de Reims, Université de Reims Champagne Ardenne, CNRS UMR 6229, UFR de Pharmacie, 51 rue Cognacq-Jay, 51096 Reims cedex, France
| | - Agathe Martinez
- UFR des Sciences Exactes et Naturelles, Bâtiment 18, Europol’Agro, BP 1039, 51687 Reims cedex 2, France
| | - Dominique Harakat
- UFR des Sciences Exactes et Naturelles, Bâtiment 18, Europol’Agro, BP 1039, 51687 Reims cedex 2, France
| | - Pascale Clivio
- Institut de Chimie Moléculaire de Reims, Université de Reims Champagne Ardenne, CNRS UMR 6229, UFR de Pharmacie, 51 rue Cognacq-Jay, 51096 Reims cedex, France
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Meza-Avina ME, Wei L, Liu Y, Poduch E, Bello AM, Mishra RK, Pai EF, Kotra LP. Structural determinants for the inhibitory ligands of orotidine-5'-monophosphate decarboxylase. Bioorg Med Chem 2010; 18:4032-41. [PMID: 20452222 DOI: 10.1016/j.bmc.2010.04.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/04/2010] [Accepted: 04/06/2010] [Indexed: 11/18/2022]
Abstract
In recent years, orotidine-5'-monophosphate decarboxylase (ODCase) has gained renewed attention as a drug target. As a part of continuing efforts to design novel inhibitors of ODCase, we undertook a comprehensive study of potent, structurally diverse ligands of ODCase and analyzed their structural interactions in the active site of ODCase. These ligands comprise of pyrazole or pyrimidine nucleotides including the mononucleotide derivatives of pyrazofurin, barbiturate ribonucleoside, and 5-cyanouridine, as well as, in a computational approach, 1,4-dihydropyridine-based non-nucleoside inhibitors such as nifedipine and nimodipine. All these ligands bind in the active site of ODCase exhibiting distinct interactions paving the way to design novel inhibitors against this interesting enzyme. We propose an empirical model for the ligand structure for rational modifications in new drug design and potentially new lead structures.
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31
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Kinetic mechanism and catalysis of Trypanosoma cruzi dihydroorotate dehydrogenase enzyme evaluated by isothermal titration calorimetry. Anal Biochem 2010; 399:13-22. [DOI: 10.1016/j.ab.2009.11.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 11/14/2009] [Accepted: 11/15/2009] [Indexed: 11/20/2022]
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32
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Bello AM, Konforte D, Poduch E, Furlonger C, Wei L, Liu Y, Lewis M, Pai EF, Paige CJ, Kotra LP. Structure-activity relationships of orotidine-5'-monophosphate decarboxylase inhibitors as anticancer agents. J Med Chem 2009; 52:1648-58. [PMID: 19260677 DOI: 10.1021/jm801224t] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of 6-substituted and 5-fluoro-6-substituted uridine derivatives were synthesized and evaluated for their potential as anticancer agents. The designed molecules were synthesized from either fully protected uridine or the corresponding 5-fluorouridine derivatives. The mononucleotide derivatives were used for enzyme inhibition investigations against ODCase. Anticancer activities of all the synthesized derivatives were evaluated using the nucleoside forms of the inhibitors. 5-Fluoro-UMP was a very weak inhibitor of ODCase. 6-Azido-5-fluoro and 5-fluoro-6-iodo derivatives are covalent inhibitors of ODCase, and the active site Lys145 residue covalently binds to the ligand after the elimination of the 6-substitution. Among the synthesized nucleoside derivatives, 6-azido-5-fluoro, 6-amino-5-fluoro, and 6-carbaldehyde-5-fluoro derivatives showed potent anticancer activities in cell-based assays against various leukemia cell lines. On the basis of the overall profile, 6-azido-5-fluoro and 6-amino-5-fluoro uridine derivatives exhibited potential for further investigations.
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Affiliation(s)
- Angelica M Bello
- Center for Molecular Design and Preformulations and Division of Cellular and Molecular Biology, Toronto General Research Institute, Toronto General Hospital, Toronto, Ontario M5G 2C4, Canada
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Fujihashi M, Bello AM, Kotra LP, Pai EF. Structural characterization of the molecular events during a slow substrate-product transition in orotidine 5'-monophosphate decarboxylase. J Mol Biol 2009; 387:1199-210. [PMID: 19236876 PMCID: PMC3125131 DOI: 10.1016/j.jmb.2009.02.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 02/05/2009] [Accepted: 02/06/2009] [Indexed: 01/07/2023]
Abstract
Crystal structures of substrate-product complexes of Methanobacterium thermoautotrophicum orotidine 5'-monophosphate decarboxylase, obtained at various steps in its catalysis of the unusual transformation of 6-cyano-uridine 5'-monophosphate (UMP) into barbituric acid ribosyl monophosphate, show that the cyano substituent of the substrate, when bound to the active site, is first bent significantly from the plane of the pyrimidine ring and then replaced by an oxygen atom. Although the K72A and D70A/K72A mutants are either catalytically impaired or even completely inactive, they still display bending of the C6 substituent. Interestingly, high-resolution structures of the D70A and D75N mutants revealed a covalent bond between C6 of UMP and the Lys72 side chain after the -CN moiety's release. The same covalent bond was observed when the native enzyme was incubated with 6-azido-UMP and 6-iodo-UMP; in contrast, the K72A mutant transformed 6-iodo-UMP to barbituric acid ribosyl 5'-monophosphate. These results demonstrate that, given a suitable environment, native orotidine 5'-monophosphate decarboxylase and several of its mutants are not restricted to the physiologically relevant decarboxylation; they are able to catalyze even nucleophilic substitution reactions but consistently maintain distortion on the C6 substituent as an important feature of catalysis.
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Affiliation(s)
- Masahiro Fujihashi
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan 606-8502, Division of Cancer Genomics & Proteomics, Ontario Cancer Institute/Princess Margaret Hospital, MaRS Centre/Toronto Medical Discovery Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada,Corresponding authors: and
| | - Angelica M. Bello
- Center for Molecular Design and Preformulations and Division of Cell and Molecular Biology, Toronto General Research Institute, MaRS Centre/Toronto Medical Discovery Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Lakshmi P. Kotra
- Center for Molecular Design and Preformulations and Division of Cell and Molecular Biology, Toronto General Research Institute, MaRS Centre/Toronto Medical Discovery Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada, Departments of Pharmaceutical Sciences and Chemistry, University of Toronto, Toronto, Ontario, Canada, Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Emil F. Pai
- Division of Cancer Genomics & Proteomics, Ontario Cancer Institute/Princess Margaret Hospital, MaRS Centre/Toronto Medical Discovery Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada, Departments of Biochemistry, Medical Biophysics and Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada,Corresponding authors: and
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Rusinov VL, Ulomskii EN, Chupakhin ON, Charushin VN. Azolo[5,1-c]-1,2,4-triazines as a new class of antiviral compounds. Russ Chem Bull 2009. [DOI: 10.1007/s11172-008-0130-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wittmann JG, Heinrich D, Gasow K, Frey A, Diederichsen U, Rudolph MG. Structures of the human orotidine-5'-monophosphate decarboxylase support a covalent mechanism and provide a framework for drug design. Structure 2008; 16:82-92. [PMID: 18184586 DOI: 10.1016/j.str.2007.10.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 10/26/2007] [Accepted: 10/26/2007] [Indexed: 02/05/2023]
Abstract
UMP synthase (UMPS) catalyzes the last two steps of de novo pyrimidine nucleotide synthesis and is a potential cancer drug target. The C-terminal domain of UMPS is orotidine-5'-monophosphate decarboxylase (OMPD), a cofactor-less yet extremely efficient enzyme. Studies of OMPDs from micro-organisms led to the proposal of several noncovalent decarboxylation mechanisms via high-energy intermediates. We describe nine crystal structures of human OMPD in complex with substrate, product, and nucleotide inhibitors. Unexpectedly, simple compounds can replace the natural nucleotides and induce a closed conformation of OMPD, defining a tripartite catalytic site. The structures outline the requirements drugs must meet to maximize therapeutic effects and minimize cross-species activity. Chemical mimicry by iodide identified a CO(2) product binding site. Plasticity of catalytic residues and a covalent OMPD-UMP complex prompt a reevaluation of the prevailing decarboxylation mechanism in favor of covalent intermediates. This mechanism can also explain the observed catalytic promiscuity of OMPD.
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Affiliation(s)
- Julia G Wittmann
- Department of Molecular Structural Biology, University of Göttingen, Göttingen, Germany
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36
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Bello AM, Poduch E, Liu Y, Wei L, Crandall I, Wang X, Dyanand C, Kain KC, Pai EF, Kotra LP. Structure-activity relationships of C6-uridine derivatives targeting plasmodia orotidine monophosphate decarboxylase. J Med Chem 2008; 51:439-48. [PMID: 18189347 DOI: 10.1021/jm7010673] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Malaria, caused by Plasmodia parasites, has re-emerged as a major problem, imposing its fatal effects on human health, especially due to multidrug resistance. In Plasmodia, orotidine 5'-monophosphate decarboxylase (ODCase) is an essential enzyme for the de novo synthesis of uridine 5'-monophosphate. Impairing ODCase in these pathogens is a promising strategy to develop novel classes of therapeutics. Encouraged by our recent discovery that 6-iodo uridine is a potent inhibitor of P. falciparum, we investigated the structure-activity relationships of various C6 derivatives of UMP. 6-Cyano, 6-azido, 6-amino, 6-methyl, 6- N-methylamino, and 6- N, N-dimethylamino derivatives of uridine were evaluated against P. falciparum. The mononucleotides of 6-cyano, 6-azido, 6-amino, and 6-methyl uridine derivatives were studied as inhibitors of plasmodial ODCase. 6-Azidouridine 5'-monophosphate is a potent covalent inhibitor of P. falciparum ODCase. 6-Methyluridine exhibited weak antimalarial activity against P. falciparum 3D7 isolate. 6- N-Methylamino and 6- N, N-dimethylamino uridine derivatives exhibited moderate antimalarial activities.
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Affiliation(s)
- Angelica M Bello
- Center for Molecular Design and Preformulations and Division of Cell and Molecular Biology, Toronto General Research Institute/University Health Network, MaRS/TMDT, Toronto, ON, Canada
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Poduch E, Wei L, Pai EF, Kotra LP. Structural diversity and plasticity associated with nucleotides targeting orotidine monophosphate decarboxylase. J Med Chem 2008; 51:432-8. [PMID: 18181562 DOI: 10.1021/jm700968x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Orotidine monophosphate decarboxylase (ODCase) generally accepts pyrimidine-based mononucleotides as ligands, but other nucleotides are also known to bind to this enzyme. We investigated the kinetic properties of eight common and endogenous nucleotides with ODCases from three species: Methanobacterium thermoautotrophicum, Plasmodium falciparum, and Homo sapiens. UMP and XMP exhibited higher affinities as compared to the other nucleotides tested. The product of ODCase catalyzed decarboxylation, UMP, displayed inhibition constants (K(i)) of 330 microM against the Mt enzyme and of 210 and 220 microM against the Pf and Hs ODCases, respectively. The K(i) values for XMP were 130 microM and 43 microM, respectively, for Mt and Pf ODCases. Interestingly, XMP's affinity for human ODCase (K(i) = 0.71 microM) is comparable and even slightly better than that of the substrate OMP. Binding of various nucleotides and their structural features in the context of ODCase inhibition and inhibitor design are discussed.
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Affiliation(s)
- Ewa Poduch
- Center for Molecular Design and Preformulations, Toronto General Research Institute, Toronto General Hospital, Toronto, ON, Canada
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38
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Okhrimenko O, Jelesarov I. A survey of the year 2006 literature on applications of isothermal titration calorimetry. J Mol Recognit 2008; 21:1-19. [DOI: 10.1002/jmr.859] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Lewis CA, Wolfenden R. Indiscriminate binding by orotidine 5'-phosphate decarboxylase of uridine 5'-phosphate derivatives with bulky anionic c6 substituents. Biochemistry 2007; 46:13331-43. [PMID: 17967036 DOI: 10.1021/bi700796t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Orotidine 5'-phosphate (OMP) decarboxylase appears to act upon its substrate without the intervention of metals or other cofactors and without the formation of covalent bonds between the enzyme and the substrate. Crystallographic information indicates that substrate binding forces the substrate's scissile carboxylate group into the neighborhood of several charged groups at the active site. It has been proposed that binding might result in electrostatic stress at the substrate's C6 carboxylate group in such a way as to promote decarboxylation by destabilizing the enzyme-substrate complex in its ground state. If that were the case, one would expect uridine 5'-phosphate (UMP) derivatives with bulky anionic substituents at C6 to be bound weakly compared with UMP, which is unsubstituted at C6. Here, we describe the formation of anionic 5,6-dihydro-6-sulfonyl derivatives by spontaneous addition of sulfite to UMP and to OMP. These sulfite addition reactions, which are slowly reversible and are not catalyzed by the enzyme, result in the appearance of one (or, in the case of OMP, two) bulky anionic substituents at the 6-carbon atom of UMP. These inhibitors are bound with affinities that surpass the binding affinity of UMP. We are led to infer that the active site of OMP decarboxylase is remarkably accommodating in the neighborhood of C6. These are not the properties that one would expect of an active site with a rigid structure that imposes sufficient electrostatic stress on the substrate to produce a major advancement along the reaction coordinate.
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Affiliation(s)
- Charles A Lewis
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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40
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Wiggers HJ, Cheleski J, Zottis A, Oliva G, Andricopulo AD, Montanari CA. Effects of organic solvents on the enzyme activity of Trypanosoma cruzi glyceraldehyde-3-phosphate dehydrogenase in calorimetric assays. Anal Biochem 2007; 370:107-14. [PMID: 17693383 DOI: 10.1016/j.ab.2007.06.042] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 06/23/2007] [Accepted: 06/26/2007] [Indexed: 11/16/2022]
Abstract
In drug discovery programs, dimethyl sulfoxide (DMSO) is a standard solvent widely used in biochemical assays. Despite the extensive use and study of enzymes in the presence of organic solvents, for some enzymes the effect of organic solvent is unknown. Macromolecular targets may be affected by the presence of different solvents in such a way that conformational changes perturb their active site structure accompanied by dramatic variations in activity when performing biochemical screenings. To address this issue, in this work we studied the effects of two organic solvents, DMSO and methanol (MeOH), in the isothermal titration calorimetry (ITC) kinetic assays for the catalyzed reaction of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Trypanosoma cruzi. The solvent effects on T. cruzi GAPDH had not yet been studied. This enzyme was shown here to be affected by the organic solvents content up to 5.0% for MeOH and up to 7.5% for DMSO. The results show that when GAPDH is assayed in the presence of DMSO (5%, v/v) using the ITC experiment, the enzyme exhibits approximately twofold higher activity than that of GAPDH with no cosolvent added. When MeOH (5%, v/v) is the cosolvent, the GAPDH activity is sixfold higher. The favorable effects of the organic solvents on the Michaelis-Menten enzyme-substrate complex formation ensure the consistency of the biological assays, structural integrity of the protein, and reproducibility over the measurement time. The reaction was also kinetically monitored by standard spectrophotometric assays to establish a behavioral performance of T. cruzi GAPDH when used for screening of potential inhibitors.
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Affiliation(s)
- H J Wiggers
- Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, SP, Brazil
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41
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Bello AM, Poduch E, Fujihashi M, Amani M, Li Y, Crandall I, Hui R, Lee PI, Kain KC, Pai EF, Kotra LP. A potent, covalent inhibitor of orotidine 5'-monophosphate decarboxylase with antimalarial activity. J Med Chem 2007; 50:915-21. [PMID: 17290979 DOI: 10.1021/jm060827p] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Orotidine 5'-monophosphate decarboxylase (ODCase) has evolved to catalyze the decarboxylation of orotidine 5'-monophosphate without any covalent intermediates. Active site residues in ODCase are involved in an extensive hydrogen-bonding network. We discovered that 6-iodouridine 5'-monophosphate (6-iodo-UMP) irreversibly inhibits the catalytic activities of ODCases from Methanobacterium thermoautotrophicum and Plasmodium falciparum. Mass spectral analysis of the enzyme-inhibitor complex confirms covalent attachment of the inhibitor to ODCase accompanied by the loss of two protons and the iodo moiety. The X-ray crystal structure (1.6 A resolution) of the complex of the inhibitor and ODCase clearly shows the covalent bond formation with the active site Lys-72 [corrected] residue. 6-Iodo-UMP inhibits ODCase in a time- and concentration-dependent fashion. 6-Iodouridine, the nucleoside form of 6-iodo-UMP, exhibited potent antiplasmodial activity, with IC50s of 4.4 +/- 1.3 microM and 6.2 +/- 0.7 microM against P. falciparum ItG and 3D7 isolates, respectively. 6-Iodouridine 5'-monophosphate is a novel covalent inhibitor of ODCase, and its nucleoside analogue paves the way to a new class of inhibitors against malaria.
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Affiliation(s)
- Angelica M Bello
- Center for Molecular Design and Preformulations, Toronto General Research Institute, Toronto General Hospital, Toronto, ON M5G 2C4 Canada
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