1
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Tian H, Xiao S, Jiang X, Tao P. PASSerRank: Prediction of allosteric sites with learning to rank. J Comput Chem 2023; 44:2223-2229. [PMID: 37561047 PMCID: PMC11127606 DOI: 10.1002/jcc.27193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/19/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023]
Abstract
Allostery plays a crucial role in regulating protein activity, making it a highly sought-after target in drug development. One of the major challenges in allosteric drug research is the identification of allosteric sites. In recent years, many computational models have been developed for accurate allosteric site prediction. Most of these models focus on designing a general rule that can be applied to pockets of proteins from various families. In this study, we present a new approach using the concept of Learning to Rank (LTR). The LTR model ranks pockets based on their relevance to allosteric sites, that is, how well a pocket meets the characteristics of known allosteric sites. After the training and validation on two datasets, the Allosteric Database (ASD) and CASBench, the LTR model was able to rank an allosteric pocket in the top three positions for 83.6% and 80.5% of test proteins, respectively. The model outperforms other common machine learning models with higher F1 scores (0.662 in ASD and 0.608 in CASBench) and Matthews correlation coefficients (0.645 in ASD and 0.589 in CASBench). The trained model is available on the PASSer platform (https://passer.smu.edu) to aid in drug discovery research.
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Affiliation(s)
- Hao Tian
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
| | - Sian Xiao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
| | - Xi Jiang
- Department of Statistics, Southern Methodist University, Dallas, Texas, USA
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
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2
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Teixeira Nunes M, Retailleau P, Raoux-Barbot D, Comisso M, Missinou AA, Velours C, Plancqueel S, Ladant D, Mechold U, Renault L. Functional and structural insights into the multi-step activation and catalytic mechanism of bacterial ExoY nucleotidyl cyclase toxins bound to actin-profilin. PLoS Pathog 2023; 19:e1011654. [PMID: 37747912 PMCID: PMC10553838 DOI: 10.1371/journal.ppat.1011654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/05/2023] [Accepted: 09/01/2023] [Indexed: 09/27/2023] Open
Abstract
ExoY virulence factors are members of a family of bacterial nucleotidyl cyclases (NCs) that are activated by specific eukaryotic cofactors and overproduce cyclic purine and pyrimidine nucleotides in host cells. ExoYs act as actin-activated NC toxins. Here, we explore the Vibrio nigripulchritudo Multifunctional-Autoprocessing Repeats-in-ToXin (MARTX) ExoY effector domain (Vn-ExoY) as a model for ExoY-type members that interact with monomeric (G-actin) instead of filamentous (F-actin) actin. Vn-ExoY exhibits moderate binding affinity to free or profilin-bound G-actin but can capture the G-actin:profilin complex, preventing its spontaneous or VASP- or formin-mediated assembly at F-actin barbed ends in vitro. This mechanism may prolong the activated cofactor-bound state of Vn-ExoY at sites of active actin cytoskeleton remodelling. We present a series of high-resolution crystal structures of nucleotide-free, 3'-deoxy-ATP- or 3'-deoxy-CTP-bound Vn-ExoY, activated by free or profilin-bound G-actin-ATP/-ADP, revealing that the cofactor only partially stabilises the nucleotide-binding pocket (NBP) of NC toxins. Substrate binding induces a large, previously-unidentified, closure of their NBP, confining catalytically important residues and metal cofactors around the substrate, and facilitating the recruitment of two metal ions to tightly coordinate the triphosphate moiety of purine or pyrimidine nucleotide substrates. We validate critical residues for both the purinyl and pyrimidinyl cyclase activity of NC toxins in Vn-ExoY and its distantly-related ExoY from Pseudomonas aeruginosa, which specifically interacts with F-actin. The data conclusively demonstrate that NC toxins employ a similar two-metal-ion mechanism for catalysing the cyclisation of nucleotides of different sizes. These structural insights into the dynamics of the actin-binding interface of actin-activated ExoYs and the multi-step activation of all NC toxins offer new perspectives for the specific inhibition of class II bacterial NC enzymes.
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Affiliation(s)
- Magda Teixeira Nunes
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Pascal Retailleau
- Université Paris Saclay, CNRS, Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France
| | - Dorothée Raoux-Barbot
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unité de Biochimie des Interactions macromoléculaires, Département de Biologie Structurale et Chimie, Paris, France
| | - Martine Comisso
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Anani Amegan Missinou
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Christophe Velours
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Stéphane Plancqueel
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Daniel Ladant
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unité de Biochimie des Interactions macromoléculaires, Département de Biologie Structurale et Chimie, Paris, France
| | - Undine Mechold
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unité de Biochimie des Interactions macromoléculaires, Département de Biologie Structurale et Chimie, Paris, France
| | - Louis Renault
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
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3
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Truong TPT, Tran TM, Dai TXT, Tran CL. Antihyperglycemic and anti-type 2 diabetic activity of marine hydroquinone isolated from brown algae (Dictyopteris polypodioides). J Tradit Complement Med 2023. [DOI: 10.1016/j.jtcme.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2023] Open
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4
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Davi M, Sadi M, Pitard I, Chenal A, Ladant D. A Robust and Sensitive Spectrophotometric Assay for the Enzymatic Activity of Bacterial Adenylate Cyclase Toxins. Toxins (Basel) 2022; 14:toxins14100691. [PMID: 36287960 PMCID: PMC9609896 DOI: 10.3390/toxins14100691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022] Open
Abstract
Various bacterial pathogens are producing toxins that target the cyclic Nucleotide Monophosphate (cNMPs) signaling pathways in order to facilitate host colonization. Among them, several are exhibiting potent nucleotidyl cyclase activities that are activated by eukaryotic factors, such as the adenylate cyclase (AC) toxin, CyaA, from Bordetella pertussis or the edema factor, EF, from Bacillus anthracis. The characterization of these toxins frequently requires accurate measurements of their enzymatic activity in vitro, in particular for deciphering their structure-to-function relationships by protein engineering and site-directed mutagenesis. Here we describe a simple and robust in vitro assay for AC activity based on the spectrophotometric detection of cyclic AMP (cAMP) after chromatographic separation on aluminum oxide. This assay can accurately detect down to fmol amounts of B. pertussis CyaA and can even be used in complex media, such as cell extracts. The relative advantages and disadvantages of this assay in comparison with other currently available methods are briefly discussed.
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Affiliation(s)
- Marilyne Davi
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, 75015 Paris, France
| | - Mirko Sadi
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, 75015 Paris, France
- Université Paris Cité, 75014 Paris, France
| | - Irene Pitard
- Structural Bioinformatic Unit, Department of Structural Biology and Chemistry, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, 75015 Paris, France
- Université Paris Sorbonne, 75231 Paris, France
| | - Alexandre Chenal
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, 75015 Paris, France
| | - Daniel Ladant
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, Université Paris Cité, CNRS UMR 3528, 75015 Paris, France
- Correspondence: ; Tel.: +33-1-4568-8400
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5
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Xiao S, Tian H, Tao P. PASSer2.0: Accurate Prediction of Protein Allosteric Sites Through Automated Machine Learning. Front Mol Biosci 2022; 9:879251. [PMID: 35898310 PMCID: PMC9309527 DOI: 10.3389/fmolb.2022.879251] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Allostery is a fundamental process in regulating protein activities. The discovery, design, and development of allosteric drugs demand better identification of allosteric sites. Several computational methods have been developed previously to predict allosteric sites using static pocket features and protein dynamics. Here, we define a baseline model for allosteric site prediction and present a computational model using automated machine learning. Our model, PASSer2.0, advanced the previous results and performed well across multiple indicators with 82.7% of allosteric pockets appearing among the top three positions. The trained machine learning model has been integrated with the Protein Allosteric Sites Server (PASSer) to facilitate allosteric drug discovery.
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Affiliation(s)
| | - Hao Tian
- *Correspondence: Hao Tian, ; Peng Tao,
| | - Peng Tao
- *Correspondence: Hao Tian, ; Peng Tao,
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6
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Teixeira-Nunes M, Retailleau P, Comisso M, Deruelle V, Mechold U, Renault L. Bacterial Nucleotidyl Cyclases Activated by Calmodulin or Actin in Host Cells: Enzyme Specificities and Cytotoxicity Mechanisms Identified to Date. Int J Mol Sci 2022; 23:ijms23126743. [PMID: 35743184 PMCID: PMC9223806 DOI: 10.3390/ijms23126743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 02/06/2023] Open
Abstract
Many pathogens manipulate host cell cAMP signaling pathways to promote their survival and proliferation. Bacterial Exoenzyme Y (ExoY) toxins belong to a family of invasive, structurally-related bacterial nucleotidyl cyclases (NC). Inactive in bacteria, they use proteins that are uniquely and abundantly present in eukaryotic cells to become potent, unregulated NC enzymes in host cells. Other well-known members of the family include Bacillus anthracis Edema Factor (EF) and Bordetella pertussis CyaA. Once bound to their eukaryotic protein cofactor, they can catalyze supra-physiological levels of various cyclic nucleotide monophosphates in infected cells. Originally identified in Pseudomonas aeruginosa, ExoY-related NC toxins appear now to be more widely distributed among various γ- and β-proteobacteria. ExoY-like toxins represent atypical, poorly characterized members within the NC toxin family. While the NC catalytic domains of EF and CyaA toxins use both calmodulin as cofactor, their counterparts in ExoY-like members from pathogens of the genus Pseudomonas or Vibrio use actin as a potent cofactor, in either its monomeric or polymerized form. This is an original subversion of actin for cytoskeleton-targeting toxins. Here, we review recent advances on the different members of the NC toxin family to highlight their common and distinct functional characteristics at the molecular, cytotoxic and enzymatic levels, and important aspects that need further characterizations.
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Affiliation(s)
- Magda Teixeira-Nunes
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
| | - Pascal Retailleau
- Institut de Chimie des Substances Naturelles (ICSN), CNRS-UPR2301, Université Paris-Saclay, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France;
| | - Martine Comisso
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
| | - Vincent Deruelle
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France; (V.D.); (U.M.)
| | - Undine Mechold
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France; (V.D.); (U.M.)
| | - Louis Renault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (M.T.-N.); (M.C.)
- Correspondence:
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7
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Tian H, Jiang X, Tao P. PASSer: Prediction of Allosteric Sites Server. MACHINE LEARNING-SCIENCE AND TECHNOLOGY 2021; 2. [PMID: 34396127 DOI: 10.1088/2632-2153/abe6d6] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Allostery is considered important in regulating protein's activity. Drug development depends on the understanding of allosteric mechanisms, especially the identification of allosteric sites, which is a prerequisite in drug discovery and design. Many computational methods have been developed for allosteric site prediction using pocket features and protein dynamics. Here, we present an ensemble learning method, consisting of eXtreme gradient boosting (XGBoost) and graph convolutional neural network (GCNN), to predict allosteric sites. Our model can learn physical properties and topology without any prior information, and shows good performance under multiple indicators. Prediction results showed that 84.9% of allosteric pockets in the test set appeared in the top 3 positions. The PASSer: Protein Allosteric Sites Server (https://passer.smu.edu), along with a command line interface (CLI, https://github.com/smutaogroup/passerCLI) provide insights for further analysis in drug discovery.
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Affiliation(s)
- Hao Tian
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
| | - Xi Jiang
- Department of Statistical Science, Southern Methodist University, Dallas, Texas, United States of America
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
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8
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Gu Y, Yang X, Shang C, Thao TTP, Koyama T. Inhibitory properties of saponin from Eleocharis dulcis peel against α-glucosidase. RSC Adv 2021; 11:15400-15409. [PMID: 35424054 PMCID: PMC8698979 DOI: 10.1039/d1ra02198b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 04/09/2021] [Indexed: 01/13/2023] Open
Abstract
The inhibitory properties towards α-glucosidase in vitro and elevation of postprandial glycemia in mice by the saponin constituent from Eleocharis dulcis peel were evaluated for the first time. Three saponins were isolated by silica gel and HPLC, identified as stigmasterol glucoside, campesterol glucoside and daucosterol by NMR spectroscopy. Daucosterol presented the highest content and showed the strongest α-glucosidase inhibitory activity with competitive inhibition. Static fluorescence quenching of α-glucosidase was caused by the formation of the daucosterol–α-glucosidase complex, which was mainly derived from hydrogen bonds and van der Waals forces. Daucosterol formed 7 hydrogen bonds with 4 residues of the active site and produced hydrophobic interactions with 3 residues located at the exterior part of the binding pocket. The maltose-loading test results showed that daucosterol inhibited elevation of postprandial glycemia in ddY mice. This suggests that daucosterol from Eleocharis dulcis peel can potentially be used as a food supplement for anti-hyperglycemia. Daucosterol from Eleocharis dulcis peel exhibits potent inhibitory activity against α-glucosidase.![]()
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Affiliation(s)
- Yipeng Gu
- Laboratory of Nutraceuticals and Functional Foods Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology 4-5-7 Konan, Minato Tokyo 108-8477 Japan
| | - Xiaomei Yang
- Institute of Food Science and Technology, Hezhou University Hezhou 542899 China
| | - Chaojie Shang
- Laboratory of Nutraceuticals and Functional Foods Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology 4-5-7 Konan, Minato Tokyo 108-8477 Japan
| | - Truong Thi Phuong Thao
- Laboratory of Nutraceuticals and Functional Foods Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology 4-5-7 Konan, Minato Tokyo 108-8477 Japan
| | - Tomoyuki Koyama
- Laboratory of Nutraceuticals and Functional Foods Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology 4-5-7 Konan, Minato Tokyo 108-8477 Japan
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9
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Pitard I, Monet D, Goossens PL, Blondel A, Malliavin TE. Analyzing In Silico the Relationship Between the Activation of the Edema Factor and Its Interaction With Calmodulin. Front Mol Biosci 2020; 7:586544. [PMID: 33344505 PMCID: PMC7746812 DOI: 10.3389/fmolb.2020.586544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 11/02/2020] [Indexed: 11/25/2022] Open
Abstract
Molecular dynamics (MD) simulations have been recorded on the complex between the edema factor (EF) of Bacilllus anthracis and calmodulin (CaM), starting from a structure with the orthosteric inhibitor adefovir bound in the EF catalytic site. The starting structure has been destabilized by alternately suppressing different co-factors, such as adefovir ligand or ions, revealing several long-distance correlations between the conformation of CaM, the geometry of the CaM/EF interface, the enzymatic site and the overall organization of the complex. An allosteric communication between CaM/EF interface and the EF catalytic site, highlighted by these correlations, was confirmed by several bioinformatics approaches from the literature. A network of hydrogen bonds and stacking interactions extending from the helix V of of CaM, and the residues of the switches A, B and C, and connecting to catalytic site residues, is a plausible candidate for the mediation of allosteric communication. The greatest variability in volume between the different MD conditions was also found for cavities present at the EF/CaM interface and in the EF catalytic site. The similarity between the predictions from literature and the volume variability might introduce the volume variability as new descriptor of allostery.
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Affiliation(s)
- Irène Pitard
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR 3528, Paris, France.,Center de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR 3756, Paris, France.,Ecole Doctorale Université Paris Sorbonne, Paris, France
| | - Damien Monet
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR 3528, Paris, France.,Center de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR 3756, Paris, France.,Ecole Doctorale Université Paris Sorbonne, Paris, France
| | | | - Arnaud Blondel
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR 3528, Paris, France.,Center de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR 3756, Paris, France
| | - Thérèse E Malliavin
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR 3528, Paris, France.,Center de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR 3756, Paris, France
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10
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Orellana L. Large-Scale Conformational Changes and Protein Function: Breaking the in silico Barrier. Front Mol Biosci 2019; 6:117. [PMID: 31750315 PMCID: PMC6848229 DOI: 10.3389/fmolb.2019.00117] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 10/14/2019] [Indexed: 12/16/2022] Open
Abstract
Large-scale conformational changes are essential to link protein structures with their function at the cell and organism scale, but have been elusive both experimentally and computationally. Over the past few years developments in cryo-electron microscopy and crystallography techniques have started to reveal multiple snapshots of increasingly large and flexible systems, deemed impossible only short time ago. As structural information accumulates, theoretical methods become central to understand how different conformers interconvert to mediate biological function. Here we briefly survey current in silico methods to tackle large conformational changes, reviewing recent examples of cross-validation of experiments and computational predictions, which show how the integration of different scale simulations with biological information is already starting to break the barriers between the in silico, in vitro, and in vivo worlds, shedding new light onto complex biological problems inaccessible so far.
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Affiliation(s)
- Laura Orellana
- Institutionen för Biokemi och Biofysik, Stockholms Universitet, Stockholm, Sweden.,Science for Life Laboratory, Solna, Sweden
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11
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Monet D, Desdouits N, Nilges M, Blondel A. mkgridXf: Consistent Identification of Plausible Binding Sites Despite the Elusive Nature of Cavities and Grooves in Protein Dynamics. J Chem Inf Model 2019; 59:3506-3518. [DOI: 10.1021/acs.jcim.9b00103] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Damien Monet
- Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, CNRS-USR 3756, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France
- Sorbonne Université, Collège doctoral, ED515 - Complexité du Vivant, 75005 Paris, France
| | - Nathan Desdouits
- Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, CNRS-USR 3756, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France
- Sorbonne Université, Collège doctoral, ED515 - Complexité du Vivant, 75005 Paris, France
| | - Michael Nilges
- Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, CNRS-USR 3756, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France
| | - Arnaud Blondel
- Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, CNRS-USR 3756, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France
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12
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Pitard I, Malliavin TE. Structural Biology and Molecular Modeling to Analyze the Entry of Bacterial Toxins and Virulence Factors into Host Cells. Toxins (Basel) 2019; 11:toxins11060369. [PMID: 31238550 PMCID: PMC6628625 DOI: 10.3390/toxins11060369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/26/2022] Open
Abstract
Understanding the functions and mechanisms of biological systems is an outstanding challenge. One way to overcome it is to combine together several approaches such as molecular modeling and experimental structural biology techniques. Indeed, the interplay between structural and dynamical properties of the system is crucial to unravel the function of molecular machinery’s. In this review, we focus on how molecular simulations along with structural information can aid in interpreting biological data. Here, we examine two different cases: (i) the endosomal translocation toxins (diphtheria, tetanus, botulinum toxins) and (ii) the activation of adenylyl cyclase inside the cytoplasm (edema factor, CyA, ExoY).
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Affiliation(s)
- Irène Pitard
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR3528, 75015 Paris, France.
- Centre de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR3756, 75015 Paris, France.
- Sorbonne Université, Collège Doctoral, Ecole Doctorale Complexité du Vivant, 75005 Paris, France.
| | - Thérèse E Malliavin
- Unité de Bioinformatique Structurale, Institut Pasteur and CNRS UMR3528, 75015 Paris, France.
- Centre de Bioinformatique, Biostatistique et Biologie Intégrative, Institut Pasteur and CNRS USR3756, 75015 Paris, France.
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13
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Spinello A, Martini S, Berti F, Pennati M, Pavlin M, Sgrignani J, Grazioso G, Colombo G, Zaffaroni N, Magistrato A. Rational design of allosteric modulators of the aromatase enzyme: An unprecedented therapeutic strategy to fight breast cancer. Eur J Med Chem 2019; 168:253-262. [DOI: 10.1016/j.ejmech.2019.02.045] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 12/29/2022]
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14
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15
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Amaral PDA, Autheman D, de Melo GD, Gouault N, Cupif JF, Goyard S, Dutra P, Coatnoan N, Cosson A, Monet D, Saul F, Haouz A, Uriac P, Blondel A, Minoprio P. Designed mono- and di-covalent inhibitors trap modeled functional motions for Trypanosoma cruzi proline racemase in crystallography. PLoS Negl Trop Dis 2018; 12:e0006853. [PMID: 30372428 PMCID: PMC6224121 DOI: 10.1371/journal.pntd.0006853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 11/08/2018] [Accepted: 09/18/2018] [Indexed: 11/19/2022] Open
Abstract
Chagas disease, caused by Trypanosoma cruzi, affects millions of people in South America and no satisfactory therapy exists, especially for its life threatening chronic phase. We targeted the Proline Racemase of T. cruzi, which is present in all stages of the parasite life cycle, to discover new inhibitors against this disease. The first published crystal structures of the enzyme revealed that the catalytic site is too small to allow any relevant drug design. In previous work, to break through the chemical space afforded to virtual screening and drug design, we generated intermediate models between the open (ligand free) and closed (ligand bound) forms of the enzyme. In the present work, we co-crystallized the enzyme with the selected inhibitors and found that they were covalently bound to the catalytic cysteine residues in the active site, thus explaining why these compounds act as irreversible inhibitors. These results led us to the design of a novel, more potent specific inhibitor, NG-P27. Co-crystallization of this new inhibitor with the enzyme allowed us to confirm the predicted protein functional motions and further characterize the chemical mechanism. Hence, the catalytic Cys300 sulfur atom of the enzyme attacks the C2 carbon of the inhibitor in a coupled, regiospecific—stereospecific Michael reaction with trans-addition of a proton on the C3 carbon. Strikingly, the six different conformations of the catalytic site in the crystal structures reported in this work had key similarities to our intermediate models previously generated by inference of the protein functional motions. These crystal structures span a conformational interval covering roughly the first quarter of the opening mechanism, demonstrating the relevance of modeling approaches to break through chemical space in drug design. There is an urgent need to develop innovative medicines addressing neglected diseases, multi-drug resistance and other unmet therapeutic needs. To create new drug design opportunities, we attempted to exploit protein functional motions by using a rational approach to model structural intermediates of a therapeutic target. After successfully designing inhibitors based on modeled intermediates of T. Cruzi proline racemase, the determination of crystal structures of the target protein in complex with the inhibitors revealed conformations that were strikingly close to the predicted models. Thus, beyond the discovery of compounds establishing a novel mode of action that can lead to innovative treatments of Chagas disease, we illustrate how modeling protein functional motions can be exploited in a rational approach to create opportunities in drug design.
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Affiliation(s)
- Patricia de Aguiar Amaral
- Université de Rennes 1, Equipe Chimie organique et interfaces (CORINT), UMR 6226 Sciences Chimiques de Rennes, Rennes, France
| | - Delphine Autheman
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Guilherme Dias de Melo
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Nicolas Gouault
- Université de Rennes 1, Equipe Chimie organique et interfaces (CORINT), UMR 6226 Sciences Chimiques de Rennes, Rennes, France
| | - Jean-François Cupif
- Université de Rennes 1, Equipe Chimie organique et interfaces (CORINT), UMR 6226 Sciences Chimiques de Rennes, Rennes, France
| | - Sophie Goyard
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Patricia Dutra
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Nicolas Coatnoan
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Alain Cosson
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
| | - Damien Monet
- Institut Pasteur, Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, Paris, France
| | - Frederick Saul
- Institut Pasteur, Plateforme de Cristallographie, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, Paris, France
| | - Ahmed Haouz
- Institut Pasteur, Plateforme de Cristallographie, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, Paris, France
| | - Philippe Uriac
- Université de Rennes 1, Equipe Chimie organique et interfaces (CORINT), UMR 6226 Sciences Chimiques de Rennes, Rennes, France
- * E-mail: (PU); (AB); (PM)
| | - Arnaud Blondel
- Institut Pasteur, Unité de Bioinformatique Structurale, Département de Biologie Structurale et Chimie, CNRS-UMR 3528, Paris, France
- * E-mail: (PU); (AB); (PM)
| | - Paola Minoprio
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Paris, France
- * E-mail: (PU); (AB); (PM)
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16
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Jiao GS, Kim S, Moayeri M, Thai A, Cregar-Hernandez L, McKasson L, O'Malley S, Leppla SH, Johnson AT. Small molecule inhibitors of anthrax edema factor. Bioorg Med Chem Lett 2017; 28:134-139. [PMID: 29198864 DOI: 10.1016/j.bmcl.2017.11.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 11/19/2022]
Abstract
Anthrax is a highly lethal disease caused by the Gram-(+) bacteria Bacillus anthracis. Edema toxin (ET) is a major contributor to the pathogenesis of disease in humans exposed to B. anthracis. ET is a bipartite toxin composed of two proteins secreted by the vegetative bacteria, edema factor (EF) and protective antigen (PA). Our work towards identifying a small molecule inhibitor of anthrax edema factor is the subject of this letter. First we demonstrate that the small molecule probe 5'-Fluorosulfonylbenzoyl 5'-adenosine (FSBA) reacts irreversibly with EF and blocks enzymatic activity. We then show that the adenosine portion of FSBA can be replaced to provide more drug-like molecules which are up to 1000-fold more potent against EF relative to FSBA, display low cross reactivity when tested against a panel of kinases, and are nanomolar inhibitors of EF in a cell-based assay of cAMP production.
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Affiliation(s)
- Guan-Sheng Jiao
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA
| | - Seongjin Kim
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - April Thai
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA
| | | | - Linda McKasson
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA
| | - Sean O'Malley
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alan T Johnson
- Hawaii Biotech, 650 Iwilei Road, Suite 204, Honolulu, HI 96817, USA.
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17
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Delarue M, Koehl P, Orland H. Ab initio sampling of transition paths by conditioned Langevin dynamics. J Chem Phys 2017; 147:152703. [PMID: 29055326 DOI: 10.1063/1.4985651] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
We propose a novel stochastic method to generate Brownian paths conditioned to start at an initial point and end at a given final point during a fixed time tf under a given potential U(x). These paths are sampled with a probability given by the overdamped Langevin dynamics. We show that these paths can be exactly generated by a local stochastic partial differential equation. This equation cannot be solved in general but we present several approximations that are valid either in the low temperature regime or in the presence of barrier crossing. We show that this method warrants the generation of statistically independent transition paths. It is computationally very efficient. We illustrate the method first on two simple potentials, the two-dimensional Mueller potential and the Mexican hat potential, and then on the multi-dimensional problem of conformational transitions in proteins using the "Mixed Elastic Network Model" as a benchmark.
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Affiliation(s)
- Marc Delarue
- Unité de Dynamique Structurale des Macromolécules, UMR 3528 du CNRS, Institut Pasteur, 75015 Paris, France
| | - Patrice Koehl
- Department of Computer Science and Genome Center, University of California, Davis, California 95616, USA
| | - Henri Orland
- Institut de Physique Théorique, CEA, URA 2306 du CNRS, F-91191 Gif-sur-Yvette, France and Beijing Computational Science Research Center, Building 9, East Zone, ZPark II, No.10 East Xibeiwang Road, Haidian District, Beijing 100193, China
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18
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Molecular Modeling of the Catalytic Domain of CyaA Deepened the Knowledge of Its Functional Dynamics. Toxins (Basel) 2017; 9:toxins9070199. [PMID: 28672846 PMCID: PMC5535146 DOI: 10.3390/toxins9070199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 12/16/2022] Open
Abstract
Although CyaA has been studied for over three decades and revealed itself to be a very good prototype for developing various biotechnological applications, only a little is known about its functional dynamics and about the conformational landscape of this protein. Molecular dynamics simulations helped to clarify the view on these points in the following way. First, the model of interaction between AC and calmodulin (CaM) has evolved from an interaction centered on the surface between C-CaM hydrophobic patch and the α helix H of AC, to a more balanced view, in which the C-terminal tail of AC along with the C-CaM Calcium loops play an important role. This role has been confirmed by the reduction of the affinity of AC for calmodulin in the presence of R338, D360 and N347 mutations. In addition, enhanced sampling studies have permitted to propose a representation of the conformational space for the isolated AC. It remains to refine this representation using structural low resolution information measured on the inactive state of AC. Finally, due to a virtual screening study on another adenyl cyclase from Bacillus anthracis, weak inhibitors of AC have been discovered.
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19
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Ripoche H, Laine E, Ceres N, Carbone A. JET2 Viewer: a database of predicted multiple, possibly overlapping, protein-protein interaction sites for PDB structures. Nucleic Acids Res 2017; 45:D236-D242. [PMID: 27899675 PMCID: PMC5210541 DOI: 10.1093/nar/gkw1053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 10/18/2016] [Accepted: 10/20/2016] [Indexed: 11/13/2022] Open
Abstract
The database JET2 Viewer, openly accessible at http://www.jet2viewer.upmc.fr/, reports putative protein binding sites for all three-dimensional (3D) structures available in the Protein Data Bank (PDB). This knowledge base was generated by applying the computational method JET2 at large-scale on more than 20 000 chains. JET2 strategy yields very precise predictions of interacting surfaces and unravels their evolutionary process and complexity. JET2 Viewer provides an online intelligent display, including interactive 3D visualization of the binding sites mapped onto PDB structures and suitable files recording JET2 analyses. Predictions were evaluated on more than 15 000 experimentally characterized protein interfaces. This is, to our knowledge, the largest evaluation of a protein binding site prediction method. The overall performance of JET2 on all interfaces are: Sen = 52.52, PPV = 51.24, Spe = 80.05, Acc = 75.89. The data can be used to foster new strategies for protein-protein interactions modulation and interaction surface redesign.
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Affiliation(s)
- Hugues Ripoche
- Sorbonne Universités, UPMC University Paris 06, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Elodie Laine
- Sorbonne Universités, UPMC University Paris 06, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Nicoletta Ceres
- CNRS UMR 5086/University Lyon I, Institut de Biologie et Chimie des Proteines, 69367 Lyon, France
| | - Alessandra Carbone
- Sorbonne Universités, UPMC University Paris 06, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France .,Institut Universitaire de France, 75005 Paris, France
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20
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Exploiting computationally derived out-of-the-box protein conformations for drug design. Future Med Chem 2016; 8:1887-1897. [PMID: 27629935 DOI: 10.4155/fmc-2016-0098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Structural plasticity is an intrinsic property of proteins that allows each gene product to accomplish its tasks in a strictly regulated manner at a precise time and cellular location. Moreover, protein motions allow protein-ligand and protein-protein recognition. The knowledge of the conformational ensemble that a drug target populates may be crucial for the design of small molecules that can differently modulate its function. X-ray crystallography and NMR have endlessly provided snapshots of protein states. However, experimental structure determination is not always straightforward. Therefore, attempts have been made to depict protein conformational landscapes through molecular dynamics and enhanced sampling methods. Here, we review how accounting for protein dynamics through in silico generated out-of-the-box protein conformations has started to impact on drug discovery.
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21
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Ma X, Qi Y, Lai L. Allosteric sites can be identified based on the residue-residue interaction energy difference. Proteins 2016; 83:1375-84. [PMID: 25185787 DOI: 10.1002/prot.24681] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/20/2014] [Accepted: 08/22/2014] [Indexed: 11/08/2022]
Abstract
Allosteric drugs act at a distance to regulate protein functions. They have several advantages over conventional orthosteric drugs, including diverse regulation types and fewer side effects. However, the rational design of allosteric ligands remains a challenge, especially when it comes to the identification allosteric binding sites. As the binding of allosteric ligands may induce changes in the pattern of residue-residue interactions, we calculated the residue-residue interaction energies within the allosteric site based on the molecular mechanics generalized Born surface area energy decomposition scheme. Using a dataset of 17 allosteric proteins with structural data for both the apo and the ligand-bound state available, we used conformational ensembles generated by molecular dynamics simulations to compute the differences in the residue-residue interaction energies in known allosteric sites from both states. For all the known sites, distinct interaction energy differences (>25%) were observed. We then used CAVITY, a binding site detection program to identify novel putative allosteric sites in the same proteins. This yielded a total of 31 "druggable binding sites," of which 21 exhibited >25% difference in residue interaction energies, and were hence predicted as novel allosteric sites. Three of the predicted allosteric sites were supported by recent experimental studies. All the predicted sites may serve as novel allosteric sites for allosteric ligand design. Our study provides a computational method for identifying novel allosteric sites for allosteric drug design.
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Affiliation(s)
- Xiaomin Ma
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Yifei Qi
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Luhua Lai
- Center for Quantitative Biology, Peking University, Beijing, 100871, China.,BNLMS, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, and Peking-Tsinghua Center for Life Sciences at College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
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22
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Affiliation(s)
- Andre A. S. T. Ribeiro
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Vanessa Ortiz
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
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23
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Local Geometry and Evolutionary Conservation of Protein Surfaces Reveal the Multiple Recognition Patches in Protein-Protein Interactions. PLoS Comput Biol 2015; 11:e1004580. [PMID: 26690684 PMCID: PMC4686965 DOI: 10.1371/journal.pcbi.1004580] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/04/2015] [Indexed: 11/19/2022] Open
Abstract
Protein-protein interactions (PPIs) are essential to all biological processes and they represent increasingly important therapeutic targets. Here, we present a new method for accurately predicting protein-protein interfaces, understanding their properties, origins and binding to multiple partners. Contrary to machine learning approaches, our method combines in a rational and very straightforward way three sequence- and structure-based descriptors of protein residues: evolutionary conservation, physico-chemical properties and local geometry. The implemented strategy yields very precise predictions for a wide range of protein-protein interfaces and discriminates them from small-molecule binding sites. Beyond its predictive power, the approach permits to dissect interaction surfaces and unravel their complexity. We show how the analysis of the predicted patches can foster new strategies for PPIs modulation and interaction surface redesign. The approach is implemented in JET2, an automated tool based on the Joint Evolutionary Trees (JET) method for sequence-based protein interface prediction. JET2 is freely available at www.lcqb.upmc.fr/JET2.
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24
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Greener JG, Sternberg MJE. AlloPred: prediction of allosteric pockets on proteins using normal mode perturbation analysis. BMC Bioinformatics 2015; 16:335. [PMID: 26493317 PMCID: PMC4619270 DOI: 10.1186/s12859-015-0771-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/13/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Despite being hugely important in biological processes, allostery is poorly understood and no universal mechanism has been discovered. Allosteric drugs are a largely unexplored prospect with many potential advantages over orthosteric drugs. Computational methods to predict allosteric sites on proteins are needed to aid the discovery of allosteric drugs, as well as to advance our fundamental understanding of allostery. RESULTS AlloPred, a novel method to predict allosteric pockets on proteins, was developed. AlloPred uses perturbation of normal modes alongside pocket descriptors in a machine learning approach that ranks the pockets on a protein. AlloPred ranked an allosteric pocket top for 23 out of 40 known allosteric proteins, showing comparable and complementary performance to two existing methods. In 28 of 40 cases an allosteric pocket was ranked first or second. The AlloPred web server, freely available at http://www.sbg.bio.ic.ac.uk/allopred/home, allows visualisation and analysis of predictions. The source code and dataset information are also available from this site. CONCLUSIONS Perturbation of normal modes can enhance our ability to predict allosteric sites on proteins. Computational methods such as AlloPred assist drug discovery efforts by suggesting sites on proteins for further experimental study.
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Affiliation(s)
- Joe G Greener
- Centre for Integrative Systems Biology and Bioinformatics, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
| | - Michael J E Sternberg
- Centre for Integrative Systems Biology and Bioinformatics, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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25
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Ohanjanian L, Remy KE, Li Y, Cui X, Eichacker PQ. An overview of investigational toxin-directed therapies for the adjunctive management of Bacillus anthracis infection and sepsis. Expert Opin Investig Drugs 2015; 24:851-65. [PMID: 25920540 DOI: 10.1517/13543784.2015.1041587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Sepsis with Bacillus anthracis infection has a very high mortality rate despite appropriate antibiotic and supportive therapies. Over the past 15 years, recent outbreaks in the US and in Europe, coupled with anthrax's bioterrorism weapon potential, have stimulated efforts to develop adjunctive therapies to improve clinical outcomes. Since lethal toxin and edema toxin (LT and ET) make central contributions to the pathogenesis of B. anthracis, these have been major targets in this effort. AREAS COVERED Here, the authors review different investigative biopharmaceuticals that have been recently identified for their therapeutic potential as inhibitors of LT or ET. Among these inhibitors are two antibody preparations that have been included in the Strategic National Stockpile (SNS) and several more that have reached Phase I testing. Presently, however, many of these candidate agents have only been studied in vitro and very few tested in bacteria-challenged models. EXPERT OPINION Although a large number of drugs have been identified as potential therapeutic inhibitors of LT and ET, in most cases their testing has been limited. The use of the two SNS antibody therapies during a large-scale exposure to B. anthracis will be difficult. Further testing and development of agents with oral bioavailability and relatively long shelf lives should be a focus for future research.
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Affiliation(s)
- Lernik Ohanjanian
- National Institutes of Health, Clinical Center, Critical Care Medicine Department , Building 10, Room 2C145, Bethesda, MD 20892 , USA +1 301 402 2914 ; +1 301 402 1213 ;
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26
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Selwa E, Davi M, Chenal A, Sotomayor-Pérez AC, Ladant D, Malliavin TE. Allosteric activation of Bordetella pertussis adenylyl cyclase by calmodulin: molecular dynamics and mutagenesis studies. J Biol Chem 2015; 289:21131-41. [PMID: 24907274 DOI: 10.1074/jbc.m113.530410] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Adenylyl cyclase (AC) toxin is an essential toxin that allows Bordetella pertussis to invade eukaryotic cells, where it is activated after binding to calmodulin (CaM). Based on the crystal structure of the AC catalytic domain in complex with the C-terminal half of CaM (C-CaM), our previous molecular dynamics simulations (Selwa, E., Laine, E., and Malliavin, T. (2012) Differential role of calmodulin and calcium ions in the stabilization of the catalytic domain of adenyl cyclase CyaA from Bordetella pertussis. Proteins 80, 1028–1040) suggested that three residues (i.e. Arg(338), Asn(347), and Asp(360)) might be important for stabilizing the AC/CaM interaction. These residues belong to a loop-helix-loop motif at the C-terminal end of AC, which is located at the interface between CaM and the AC catalytic loop. In the present study, we conducted the in silico and in vitro characterization of three AC variants, where one (Asn(347); ACm1A), two (Arg(338) and Asp(360); ACm2A), or three residues (Arg(338), Asn(347), and Asp(360); ACm3A) were substituted with Ala. Biochemical studies showed that the affinities of ACm1A and ACm2A for CaM were not affected significantly, whereas that of ACm3A was reduced dramatically. To understand the effects of these modifications, molecular dynamics simulations were performed based on the modified proteins. The molecular dynamics trajectories recorded for the ACm3AC-CaM complex showed that the calcium-binding loops of C-CaM exhibited large fluctuations, which could be related to the weakened interaction between ACm3A and its activator. Overall, our results suggest that the loop-helix-loop motif at the C-terminal end of AC is crucial during CaM binding for stabilizing the AC catalytic loop in an active configuration.
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27
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Cortés-Ciriano I, Ain QU, Subramanian V, Lenselink EB, Méndez-Lucio O, IJzerman AP, Wohlfahrt G, Prusis P, Malliavin TE, van Westen GJP, Bender A. Polypharmacology modelling using proteochemometrics (PCM): recent methodological developments, applications to target families, and future prospects. MEDCHEMCOMM 2015. [DOI: 10.1039/c4md00216d] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proteochemometric (PCM) modelling is a computational method to model the bioactivity of multiple ligands against multiple related protein targets simultaneously.
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Affiliation(s)
- Isidro Cortés-Ciriano
- Unité de Bioinformatique Structurale
- Institut Pasteur and CNRS UMR 3825
- Structural Biology and Chemistry Department
- 75 724 Paris
- France
| | - Qurrat Ul Ain
- Unilever Centre for Molecular Informatics
- Department of Chemistry
- CB2 1EW Cambridge
- UK
| | | | - Eelke B. Lenselink
- Division of Medicinal Chemistry
- Leiden Academic Centre for Drug Research
- Leiden
- The Netherlands
| | - Oscar Méndez-Lucio
- Unilever Centre for Molecular Informatics
- Department of Chemistry
- CB2 1EW Cambridge
- UK
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry
- Leiden Academic Centre for Drug Research
- Leiden
- The Netherlands
| | - Gerd Wohlfahrt
- Computer-Aided Drug Design
- Orion Pharma
- FIN-02101 Espoo
- Finland
| | - Peteris Prusis
- Computer-Aided Drug Design
- Orion Pharma
- FIN-02101 Espoo
- Finland
| | - Thérèse E. Malliavin
- Unité de Bioinformatique Structurale
- Institut Pasteur and CNRS UMR 3825
- Structural Biology and Chemistry Department
- 75 724 Paris
- France
| | - Gerard J. P. van Westen
- European Molecular Biology Laboratory
- European Bioinformatics Institute
- Wellcome Trust Genome Campus
- Hinxton
- UK
| | - Andreas Bender
- Unilever Centre for Molecular Informatics
- Department of Chemistry
- CB2 1EW Cambridge
- UK
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28
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Principal Component Analysis reveals correlation of cavities evolution and functional motions in proteins. J Mol Graph Model 2014; 55:13-24. [PMID: 25424655 DOI: 10.1016/j.jmgm.2014.10.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/16/2014] [Accepted: 10/18/2014] [Indexed: 11/24/2022]
Abstract
Protein conformation has been recognized as the key feature determining biological function, as it determines the position of the essential groups specifically interacting with substrates. Hence, the shape of the cavities or grooves at the protein surface appears to drive those functions. However, only a few studies describe the geometrical evolution of protein cavities during molecular dynamics simulations (MD), usually with a crude representation. To unveil the dynamics of cavity geometry evolution, we developed an approach combining cavity detection and Principal Component Analysis (PCA). This approach was applied to four systems subjected to MD (lysozyme, sperm whale myoglobin, Dengue envelope protein and EF-CaM complex). PCA on cavities allows us to perform efficient analysis and classification of the geometry diversity explored by a cavity. Additionally, it reveals correlations between the evolutions of the cavities and structures, and can even suggest how to modify the protein conformation to induce a given cavity geometry. It also helps to perform fast and consensual clustering of conformations according to cavity geometry. Finally, using this approach, we show that both carbon monoxide (CO) location and transfer among the different xenon sites of myoglobin are correlated with few cavity evolution modes of high amplitude. This correlation illustrates the link between ligand diffusion and the dynamic network of internal cavities.
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29
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Selwa E, Huynh T, Ciccotti G, Maragliano L, Malliavin TE. Temperature-accelerated molecular dynamics gives insights into globular conformations sampled in the free state of the AC catalytic domain. Proteins 2014; 82:2483-96. [PMID: 24863163 DOI: 10.1002/prot.24612] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 05/05/2014] [Accepted: 05/13/2014] [Indexed: 01/16/2023]
Abstract
The catalytic domain of the adenyl cyclase (AC) toxin from Bordetella pertussis is activated by interaction with calmodulin (CaM), resulting in cAMP overproduction in the infected cell. In the X-ray crystallographic structure of the complex between AC and the C terminal lobe of CaM, the toxin displays a markedly elongated shape. As for the structure of the isolated protein, experimental results support the hypothesis that more globular conformations are sampled, but information at atomic resolution is still lacking. Here, we use temperature-accelerated molecular dynamics (TAMD) simulations to generate putative all-atom models of globular conformations sampled by CaM-free AC. As collective variables, we use centers of mass coordinates of groups of residues selected from the analysis of standard molecular dynamics (MD) simulations. Results show that TAMD allows extended conformational sampling and generates AC conformations that are more globular than in the complexed state. These structures are then refined via energy minimization and further unrestrained MD simulations to optimize inter-domain packing interactions, thus resulting in the identification of a set of hydrogen bonds present in the globular conformations.
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Affiliation(s)
- Edithe Selwa
- Institut Pasteur and CNRS UMR 3528, rue du Dr Roux, Unité de Bioinformatique Structurale, 75015, Paris, France; Université Pierre et Marie Curie, Cellule Pasteur UPMC, rue du Dr Roux, 75015, Paris, France
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30
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Abstract
INTRODUCTION Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded 'for the development of multiscale models for complex chemical systems' once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial-and-error approach to a minimum. The intentional dissemination of Bacillus anthracis spores in 2001 via the so-called anthrax letters has led to increased efforts, politically and scientifically, to develop medical countermeasures that will protect people from the threat of anthrax bioterrorism. AREAS COVERED This article provides an overview of the recent rational drug design approaches for discovering inhibitors of anthrax toxin. The review also directs the readers to the vast literature on the recognized advances and future possibilities in the field. EXPERT OPINION Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (protective antigen-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, the situation, in our view, is still insecure. Further, the FDA's animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Better identification and validation of anthrax toxin therapeutic targets at the molecular level as well as elucidation of the parameters determining the corresponding therapeutic windows are still necessary for more effective therapeutic options.
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Affiliation(s)
- Ekaterina M Nestorovich
- The Catholic University of America, Department of Biology , Washington, DC , USA +1 202 319 6723 ;
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31
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Xia Y, DiPrimio N, Keppel TR, Vo B, Fraser K, Battaile KP, Egan C, Bystroff C, Lovell S, Weis DD, Anderson JC, Karanicolas J. The designability of protein switches by chemical rescue of structure: mechanisms of inactivation and reactivation. J Am Chem Soc 2013; 135:18840-9. [PMID: 24313858 DOI: 10.1021/ja407644b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ability to selectively activate function of particular proteins via pharmacological agents is a longstanding goal in chemical biology. Recently, we reported an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. However, rationally identifying analogous de novo binding sites in other enzymes represents a key challenge for extending this approach to introduce allosteric control into other enzymes. Here we show that mutation sites leading to protein inactivation via tryptophan-to-glycine substitution and allowing (partial) reactivation by the subsequent addition of indole are remarkably frequent. Through a suite of methods including a cell-based reporter assay, computational structure prediction and energetic analysis, fluorescence studies, enzymology, pulse proteolysis, X-ray crystallography, and hydrogen-deuterium mass spectrometry, we find that these switchable proteins are most commonly modulated indirectly, through control of protein stability. Addition of indole in these cases rescues activity not by reverting a discrete conformational change, as we had observed in the sole previously reported example, but rather rescues activity by restoring protein stability. This important finding will dramatically impact the design of future switches and sensors built by this approach, since evaluating stability differences associated with cavity-forming mutations is a far more tractable task than predicting allosteric conformational changes. By analogy to natural signaling systems, the insights from this study further raise the exciting prospect of modulating stability to design optimal recognition properties into future de novo switches and sensors built through chemical rescue of structure.
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Affiliation(s)
- Yan Xia
- Department of Molecular Biosciences, ‡Department of Chemistry, §Protein Structure Laboratory, and ∥Center for Bioinformatics, University of Kansas , Lawrence, Kansas 66045, United States
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32
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Seifert R, Dove S. Inhibitors of Bacillus anthracis edema factor. Pharmacol Ther 2013; 140:200-12. [PMID: 23850654 DOI: 10.1016/j.pharmthera.2013.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/17/2013] [Indexed: 01/09/2023]
Abstract
Edema factor (EF) is a calmodulin (CaM)-activated adenylyl cyclase (AC) toxin from Bacillus anthracis that contributes to anthrax pathogenesis. Anthrax is an important medical problem, but treatment of B. anthracis infections is still unsatisfying. Thus, selective EF inhibitors could be valuable drugs in the treatment of anthrax infection, most importantly shock. The catalytic site of EF, the EF/CaM interaction site and allosteric sites constitute potential drug targets. To this end, most efforts have been directed towards targeting the catalytic site. A major challenge in the field is to obtain compounds with high selectivity for AC toxins relative to mammalian membranous ACs (mACs). 3'-(N-methyl)anthraniloyl-2'-deoxyadenosine-5'-triphosphate is the most potent EF inhibitor known so far (Ki, 10nM), but selectivity relative to mACs needs to be improved (currently ~5-50-fold, depending on the specific mAC isoform considered). AC toxin inhibitors can be identified in virtual screening studies based on available EF crystal structures and examined in cellular test systems or at the level of purified toxin using classic radioisotopic or non-radioactive fluorescence assays. Binding of certain MANT-nucleotides to AC toxins elicits large direct fluorescence- or fluorescence resonance energy transfer signals upon interaction with CaM, and these signals can be used to identify toxin inhibitors in competition binding studies. Collectively, potent EF inhibitors are available, but before they can be used clinically, selectivity against mACs must be improved. However, several methodological approaches, complementing each other, are now available to direct the development of potent, selective, orally applicable and clinically useful EF inhibitors.
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Affiliation(s)
- Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
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33
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Berneman A, Montout L, Goyard S, Chamond N, Cosson A, d’Archivio S, Gouault N, Uriac P, Blondel A, Minoprio P. Combined approaches for drug design points the way to novel proline racemase inhibitor candidates to fight Chagas' disease. PLoS One 2013; 8:e60955. [PMID: 23613764 PMCID: PMC3628851 DOI: 10.1371/journal.pone.0060955] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 03/04/2013] [Indexed: 11/18/2022] Open
Abstract
Chagas' disease is caused by Trypanosoma cruzi, a protozoan transmitted to humans by blood-feeding insects, blood transfusion or congenitally. Previous research led us to discover a parasite proline racemase (TcPRAC) and to establish its validity as a target for the design of new chemotherapies against the disease, including its chronic form. A known inhibitor of proline racemases, 2-pyrrolecarboxylic acid (PYC), is water-insoluble. We synthesized soluble pyrazole derivatives, but they proved weak or inactive TcPRAC inhibitors. TcPRAC catalytic site is too small and constrained when bound to PYC to allow efficient search for new inhibitors by virtual screening. Forty-nine intermediate conformations between the opened enzyme structure and the closed liganded one were built by calculating a transition path with a method we developed. A wider range of chemical compounds could dock in the partially opened intermediate active site models in silico. Four models were selected for known substrates and weak inhibitors could dock in them and were used to screen chemical libraries. Two identified soluble compounds, (E)-4-oxopent-2-enoic acid (OxoPA) and its derivative (E)-5-bromo-4-oxopent-2-enoic acid (Br-OxoPA), are irreversible competitive inhibitors that presented stronger activity than PYC on TcPRAC. We show here that increasing doses of OxoPA and Br-OxoPA hamper T. cruzi intracellular differentiation and fate in mammalian host cells. Our data confirm that through to their binding mode, these molecules are interesting and promising as lead compounds for the development of chemotherapies against diseases where active proline racemases play essential roles.
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Affiliation(s)
- Armand Berneman
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
| | - Lory Montout
- Unité de Bioinformatique Structurale, CNRS-UMR 3528, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
| | - Sophie Goyard
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
| | - Nathalie Chamond
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
| | - Alain Cosson
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
| | - Simon d’Archivio
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
| | - Nicolas Gouault
- Equipe Produits Naturels, Synthèses et Chimie Médicinale, UMR 6226 Sciences Chimiques de Rennes, Université de Rennes 1, Rennes, France
| | - Philippe Uriac
- Equipe Produits Naturels, Synthèses et Chimie Médicinale, UMR 6226 Sciences Chimiques de Rennes, Université de Rennes 1, Rennes, France
| | - Arnaud Blondel
- Unité de Bioinformatique Structurale, CNRS-UMR 3528, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
| | - Paola Minoprio
- Laboratoire des Processus Infectieux à Trypanosomatidés, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
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34
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Milko P, Roithová J, Schug KA, Lemr K. Impact of long-range van der Waals forces on chiral recognition in a Cinchona alkaloid chiral selector system. Phys Chem Chem Phys 2013; 15:6113-21. [DOI: 10.1039/c3cp44444a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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35
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Abstract
This review will highlight the most commonly used methods to discover small molecule Type III/IV kinase inhibitors.
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Affiliation(s)
- Lori Krim Gavrin
- Pfizer Research
- Rare Disease Chemistry and Chemical Biology
- BioTherapeutics Chemistry
- Cambridge
- USA
| | - Eddine Saiah
- Pfizer Research
- Rare Disease Chemistry and Chemical Biology
- BioTherapeutics Chemistry
- Cambridge
- USA
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36
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Laine É, Martínez L, Ladant D, Malliavin T, Blondel A. Molecular motions as a drug target: mechanistic simulations of anthrax toxin edema factor function led to the discovery of novel allosteric inhibitors. Toxins (Basel) 2012; 4:580-604. [PMID: 23012649 PMCID: PMC3446745 DOI: 10.3390/toxins4080580] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 07/04/2012] [Accepted: 07/18/2012] [Indexed: 01/14/2023] Open
Abstract
Edema Factor (EF) is a component of Bacillus anthracis toxin essential for virulence. Its adenylyl cyclase activity is induced by complexation with the ubiquitous eukaryotic cellular protein, calmodulin (CaM). EF and its complexes with CaM, nucleotides and/or ions, have been extensively characterized by X-ray crystallography. Those structural data allowed molecular simulations analysis of various aspects of EF action mechanism, including the delineation of EF and CaM domains through their association energetics, the impact of calcium binding on CaM, and the role of catalytic site ions. Furthermore, a transition path connecting the free inactive form to the CaM-complexed active form of EF was built to model the activation mechanism in an attempt to define an inhibition strategy. The cavities at the surface of EF were determined for each path intermediate to identify potential sites where the binding of a ligand could block activation. A non-catalytic cavity (allosteric) was found to shrink rapidly at early stages of the path and was chosen to perform virtual screening. Amongst 18 compounds selected in silico and tested in an enzymatic assay, 6 thiophen ureidoacid derivatives formed a new family of EF allosteric inhibitors with IC50 as low as 2 micromolars.
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Affiliation(s)
- Élodie Laine
- Laboratoire de Biologie et de Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, 61, avenue du Président Wilson, 94235 Cachan cedex, France;
| | - Leandro Martínez
- The Molecular Biotechnology Group, Institute of Physics of São Carlos, University of São Paulo, Av. Trabalhador Sãocarlense, 400, 13566-590 São Carlos, SP, Brazil;
| | - Daniel Ladant
- Unité de Biochimie des Interactions Macromoléculaires and CNRS UMR 3528, Département de Biologie Structurale et Chimie, Institut Pasteur, 28, rue du Dr. Roux, 75724 Paris Cedex 15, France;
| | - Thérèse Malliavin
- Unité de Bioinformatique Structurale and CNRS UMR 3528, Département de Biologie Structurale et Chimie, Institut Pasteur, 25, rue du Dr. Roux, 75724 Paris Cedex 15, France;
| | - Arnaud Blondel
- Unité de Bioinformatique Structurale and CNRS UMR 3528, Département de Biologie Structurale et Chimie, Institut Pasteur, 25, rue du Dr. Roux, 75724 Paris Cedex 15, France;
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37
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Qi Y, Wang Q, Tang B, Lai L. Identifying Allosteric Binding Sites in Proteins with a Two-State Go̅ Model for Novel Allosteric Effector Discovery. J Chem Theory Comput 2012; 8:2962-71. [DOI: 10.1021/ct300395h] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yifei Qi
- BNLMS,
State Key Laboratory for Structural Chemistry of Unstable and Stable
Species, and Peking−Tsinghua Center for Life Sciences at College
of Chemistry and Molecular Engineering and ‡Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Qian Wang
- BNLMS,
State Key Laboratory for Structural Chemistry of Unstable and Stable
Species, and Peking−Tsinghua Center for Life Sciences at College
of Chemistry and Molecular Engineering and ‡Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Bo Tang
- BNLMS,
State Key Laboratory for Structural Chemistry of Unstable and Stable
Species, and Peking−Tsinghua Center for Life Sciences at College
of Chemistry and Molecular Engineering and ‡Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Luhua Lai
- BNLMS,
State Key Laboratory for Structural Chemistry of Unstable and Stable
Species, and Peking−Tsinghua Center for Life Sciences at College
of Chemistry and Molecular Engineering and ‡Center for Quantitative Biology, Peking University, Beijing 100871, China
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38
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Göttle M, Dove S, Seifert R. Bacillus anthracis edema factor substrate specificity: evidence for new modes of action. Toxins (Basel) 2012; 4:505-35. [PMID: 22852066 PMCID: PMC3407890 DOI: 10.3390/toxins4070505] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 06/15/2012] [Accepted: 06/27/2012] [Indexed: 12/20/2022] Open
Abstract
Since the isolation of Bacillus anthracis exotoxins in the 1960s, the detrimental activity of edema factor (EF) was considered as adenylyl cyclase activity only. Yet the catalytic site of EF was recently shown to accomplish cyclization of cytidine 5'-triphosphate, uridine 5'-triphosphate and inosine 5'-triphosphate, in addition to adenosine 5'-triphosphate. This review discusses the broad EF substrate specificity and possible implications of intracellular accumulation of cyclic cytidine 3':5'-monophosphate, cyclic uridine 3':5'-monophosphate and cyclic inosine 3':5'-monophosphate on cellular functions vital for host defense. In particular, cAMP-independent mechanisms of action of EF on host cell signaling via protein kinase A, protein kinase G, phosphodiesterases and CNG channels are discussed.
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Affiliation(s)
- Martin Göttle
- Department of Neurology, Emory University School of Medicine, 6302 Woodruff Memorial Research Building, 101 Woodruff Circle, Atlanta, GA 30322, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-404-727-1678; Fax: +1-404-727-3157
| | - Stefan Dove
- Department of Medicinal/Pharmaceutical Chemistry II, University of Regensburg, D-93040 Regensburg, Germany;
| | - Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany;
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39
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Deckert K, Budiardjo SJ, Brunner LC, Lovell S, Karanicolas J. Designing allosteric control into enzymes by chemical rescue of structure. J Am Chem Soc 2012; 134:10055-60. [PMID: 22655749 DOI: 10.1021/ja301409g] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ligand-dependent activity has been engineered into enzymes for purposes ranging from controlling cell morphology to reprogramming cellular signaling pathways. Where these successes have typically fused a naturally allosteric domain to the enzyme of interest, here we instead demonstrate an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. We present two examples, W33G in a β-glycosidase enzyme (β-gly) and W492G in a β-glucuronidase enzyme (β-gluc), in which we engineer indole-dependent activity into enzymes by removing a buried tryptophan side chain that serves as a buttress for the active site architecture. In both cases, we observe a loss of function, and in both cases we find that the subsequent addition of indole can be used to restore activity. Through a detailed analysis of β-gly W33G kinetics, we demonstrate that this rescued enzyme is fully functionally equivalent to the corresponding wild-type enzyme. We then present the apo and indole-bound crystal structures of β-gly W33G, which together establish the structural basis for enzyme inactivation and rescue. Finally, we use this designed switch to modulate β-glycosidase activity in living cells using indole. Disruption and recovery of protein structure may represent a general technique for introducing allosteric control into enzymes, and thus may serve as a starting point for building a variety of bioswitches and sensors.
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Affiliation(s)
- Katelyn Deckert
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas 66045-7534, USA
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40
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Taboureau O, Baell JB, Fernández-Recio J, Villoutreix BO. Established and emerging trends in computational drug discovery in the structural genomics era. ACTA ACUST UNITED AC 2012; 19:29-41. [PMID: 22284352 DOI: 10.1016/j.chembiol.2011.12.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 12/05/2011] [Accepted: 12/08/2011] [Indexed: 12/01/2022]
Abstract
Bioinformatics and chemoinformatics approaches contribute to hit discovery, hit-to-lead optimization, safety profiling, and target identification and enhance our overall understanding of the health and disease states. A vast repertoire of computational methods has been reported and increasingly combined in order to address more and more challenging targets or complex molecular mechanisms in the context of large-scale integration of structure and bioactivity data produced by private and public drug research. This review explores some key computational methods directly linked to drug discovery and chemical biology with a special emphasis on compound collection preparation, virtual screening, protein docking, and systems pharmacology. A list of generally freely available software packages and online resources is provided, and examples of successful applications are briefly commented upon.
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Affiliation(s)
- Olivier Taboureau
- Center for Biological Sequences Analysis, Department of Systems Biology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
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41
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Towards selective inhibitors of adenylyl cyclase toxin from Bordetella pertussis. Trends Microbiol 2012; 20:343-51. [PMID: 22578665 DOI: 10.1016/j.tim.2012.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 12/19/2022]
Abstract
Whooping cough is a very important medical problem that requires novel approaches for treatment. The disease is caused by Bordetella pertussis, with the calmodulin (CaM)-activated adenylyl cyclase (AC) toxin (also known as CyaA) being a major virulence factor. Hence, CyaA inhibitors could constitute novel therapeutics, but it has been difficult to develop potent drugs with high selectivity over mammalian membranous ACs (mACs). Recent studies have shown that bis-anthraniloyl-substituted nucleoside 5'-triphosphates are potent and selective CyaA inhibitors. In addition, the interaction of CyaA with CaM is very different from the interaction of membranous mAC1 with CaM. Accordingly, compounds that interfere with the CyaA-CaM interaction may constitute a novel class of drugs against whooping cough.
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42
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Beierlein JM, Anderson AC. New developments in vaccines, inhibitors of anthrax toxins, and antibiotic therapeutics for Bacillus anthracis. Curr Med Chem 2012; 18:5083-94. [PMID: 22050756 DOI: 10.2174/092986711797636036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 09/07/2011] [Accepted: 09/09/2011] [Indexed: 01/28/2023]
Abstract
Bacillus anthracis, the causative agent responsible for anthrax infections, poses a significant biodefense threat. There is a high mortality rate associated with untreated anthrax infections; specifically, inhalation anthrax is a particularly virulent form of infection with mortality rates close to 100%, even with aggressive treatment. Currently, a vaccine is not available to the general public and few antibiotics have been approved by the FDA for the treatment of inhalation anthrax. With the threat of natural or engineered bacterial resistance to antibiotics and the limited population for whom the current drugs are approved, there is a clear need for more effective treatments against this deadly infection. A comprehensive review of current research in drug discovery is presented in this article, including efforts to improve the purity and stability of vaccines, design inhibitors targeting the anthrax toxins, and identify inhibitors of novel enzyme targets. High resolution structural information for the anthrax toxins and several essential metabolic enzymes has played a significant role in aiding the structure-based design of potent and selective antibiotics.
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Affiliation(s)
- J M Beierlein
- Dept. Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, USA
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43
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Ivarsson ME, Leroux JC, Castagner B. Targeting bacterial toxins. Angew Chem Int Ed Engl 2012; 51:4024-45. [PMID: 22441768 DOI: 10.1002/anie.201104384] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/21/2011] [Indexed: 12/18/2022]
Abstract
Protein toxins constitute the main virulence factors of several species of bacteria and have proven to be attractive targets for drug development. Lead candidates that target bacterial toxins range from small molecules to polymeric binders, and act at each of the multiple steps in the process of toxin-mediated pathogenicity. Despite recent and significant advances in the field, a rationally designed drug that targets toxins has yet to reach the market. This Review presents the state of the art in bacterial toxin targeted drug development with a critical consideration of achieved breakthroughs and withstanding challenges. The discussion focuses on A-B-type protein toxins secreted by four species of bacteria, namely Clostridium difficile (toxins A and B), Vibrio cholerae (cholera toxin), enterohemorrhagic Escherichia coli (Shiga toxin), and Bacillus anthracis (anthrax toxin), which are the causative agents of diseases for which treatments need to be improved.
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Affiliation(s)
- Mattias E Ivarsson
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich, Wolfgang-Pauli-Strasse 10, Zurich, Switzerland
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44
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45
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Schuler D, Lübker C, Lushington GH, Tang WJ, Shen Y, Richter M, Seifert R. Interactions of Bordetella pertussis adenylyl cyclase toxin CyaA with calmodulin mutants and calmodulin antagonists: comparison with membranous adenylyl cyclase I. Biochem Pharmacol 2012; 83:839-848. [PMID: 22265637 DOI: 10.1016/j.bcp.2012.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/03/2012] [Accepted: 01/04/2012] [Indexed: 01/12/2023]
Abstract
The adenylyl cyclase (AC) toxin CyaA from Bordetella pertussis constitutes an important virulence factor for the pathogenesis of whooping cough. CyaA is activated by calmodulin (CaM) and compromises host defense by excessive cAMP production. Hence, pharmacological modulation of the CyaA/CaM interaction could constitute a promising approach to treat whooping cough, provided that interactions of endogenous effector proteins with CaM are not affected. As a first step toward this ambitious goal we examined the interactions of CyaA with wild-type CaM and four CaM mutants in which most methionine residues were replaced by leucine residues and studied the effects of the CaM antagonists calmidazolium, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). CyaA/CaM interaction was monitored by CaM-dependent fluorescence resonance energy transfer (FRET) between tryptophan residues in CyaA and 2'-(N-methylanthraniloyl)-3'-deoxy-adenosine 5'-triphosphate and catalytic activity. Comparison of the concentration/response curves of CaM and CaM mutants for FRET and catalysis revealed differences, suggesting a two-step activation mechanism of CyaA by CaM. Even in the absence of CaM, calmidazolium inhibited catalysis, and it did so according to a biphasic function. Trifluoperazine and W-7 did not inhibit FRET or catalysis. In contrast to CyaA, some CaM mutants were more efficacious than CaM at activating membranous AC isoform 1. The slope of CyaA activation by CaM was much steeper than of AC1 activation. Collectively, the two-step activation mechanism of CyaA by CaM offers opportunities for pharmacological intervention. The failure of classic CaM inhibitors to interfere with CyaA/CaM interactions and the different interactions of CaM mutants with CyaA and AC1 point to unique CyaA/CaM interactions.
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Affiliation(s)
- Dominik Schuler
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Carolin Lübker
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Gerald H Lushington
- Molecular Graphics and Modeling Laboratory, The University of Kansas, KS 66045, USA
| | - Wei-Jen Tang
- Ben May Department of Cancer Research, The University of Chicago, Chicago, IL 60637, USA
| | - Yuequan Shen
- College of Life Sciences, Nankai University, 300071 Tianjin, People's Republic of China
| | - Mark Richter
- Department of Molecular Biosciences, The University of Kansas, Lawrence, KS 66045, USA
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
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Karst JC, Barker R, Devi U, Swann MJ, Davi M, Roser SJ, Ladant D, Chenal A. Identification of a region that assists membrane insertion and translocation of the catalytic domain of Bordetella pertussis CyaA toxin. J Biol Chem 2012; 287:9200-12. [PMID: 22241477 DOI: 10.1074/jbc.m111.316166] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The adenylate cyclase (CyaA) toxin, one of the virulence factors secreted by Bordetella pertussis, the pathogenic bacteria responsible for whooping cough, plays a critical role in the early stages of respiratory tract colonization by this bacterium. The CyaA toxin is able to invade eukaryotic cells by translocating its N-terminal catalytic domain directly across the plasma membrane of the target cells, where, activated by endogenous calmodulin, it produces supraphysiological levels of cAMP. How the catalytic domain is transferred from the hydrophilic extracellular medium into the hydrophobic environment of the membrane and then to the cell cytoplasm remains an unsolved question. In this report, we have characterized the membrane-interacting properties of the CyaA catalytic domain. We showed that a protein covering the catalytic domain (AC384, encompassing residues 1-384 of CyaA) displayed no membrane association propensity. However, a longer polypeptide (AC489), encompassing residues 1-489 of CyaA, exhibited the intrinsic property to bind to membranes and to induce lipid bilayer destabilization. We further showed that deletion of residues 375-485 within CyaA totally abrogated the toxin's ability to increase intracellular cAMP in target cells. These results indicate that, whereas the calmodulin dependent enzymatic domain is restricted to the amino-terminal residues 1-384 of CyaA, the membrane-interacting, translocation-competent domain extends up to residue 489. This thus suggests an important role of the region adjacent to the catalytic domain of CyaA in promoting its interaction with and its translocation across the plasma membrane of target cells.
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Affiliation(s)
- Johanna C Karst
- Institut Pasteur, CNRS UMR 3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, Paris, France
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47
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Selwa E, Laine E, Malliavin TE. Differential role of calmodulin and calcium ions in the stabilization of the catalytic domain of adenyl cyclase CyaA from Bordetella pertussis. Proteins 2012; 80:1028-40. [DOI: 10.1002/prot.24005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Revised: 11/04/2011] [Accepted: 11/14/2011] [Indexed: 11/10/2022]
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48
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Makiya M, Dolan M, Agulto L, Purcell R, Chen Z. Structural basis of anthrax edema factor neutralization by a neutralizing antibody. Biochem Biophys Res Commun 2012; 417:324-9. [PMID: 22155239 PMCID: PMC3293246 DOI: 10.1016/j.bbrc.2011.11.108] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 11/19/2011] [Indexed: 11/16/2022]
Abstract
Fine epitope mapping of EF13D, a highly potent neutralizing monoclonal antibody specific for the anthrax edema factor (EF), was accomplished through random mutagenesis and yeast surface display. A yeast-displayed library of single point mutants of an EF domain III (DIII), comprising amino acids 624-800, was constructed by random mutagenesis and screened for reduced binding to EF13D. With this method, residues Leu 667, Ser 668, Arg 671, and Arg 672 were identified as key residues important for EF13D binding. They form a contiguous patch on a solvent-exposed surface at one end of the four-helix bundle of DIII. Computational protein-protein docking experiments between anEF13D model and a crystal structure of EF indicate that the EF13D heavy chain complementarity-determining region 3 (HCDR3) is deeply buried within a hydrophobic cleft between two helices of DIII and interacts directly with residues Leu 667, Ser 668, Arg 671 and Arg 672, providing an explanation for the high binding affinity. In addition, they show that the HCDR3 binding site overlaps with the binding site of the N-terminal lobe of calmodulin (CaM), an EF enzymatic activator, consistent with a previous finding showing direct competition with CaM that results in neutralization of EF. Identifying the neutralization epitope of EF13D on EF improves our understanding of the neutralization mechanism and has implications for vaccine development.
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Affiliation(s)
- Michelle Makiya
- Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, MD20892
| | - Michael Dolan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD20892
| | - Liane Agulto
- Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, MD20892
| | - Robert Purcell
- Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, MD20892
| | - Zhaochun Chen
- Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, MD20892
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49
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Chen D, Ma L, Kanalas JJ, Gao J, Pawlik J, Jimenez ME, Walter MA, Peterson JW, Gilbertson SR, Schein CH. Structure-based redesign of an edema toxin inhibitor. Bioorg Med Chem 2012; 20:368-76. [PMID: 22154558 PMCID: PMC3251925 DOI: 10.1016/j.bmc.2011.10.091] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/17/2011] [Accepted: 10/25/2011] [Indexed: 11/17/2022]
Abstract
Edema factor (EF) toxin of Bacillus anthracis (NIAID category A), and several other toxins from NIAID category B Biodefense target bacteria are adenylyl cyclases or adenylyl cyclase agonists that catalyze the conversion of ATP to 3',5'-cyclic adenosine monophosphate (cAMP). We previously identified compound 1 (3-[(9-oxo-9H-fluorene-1-carbonyl)-amino]-benzoic acid), that inhibits EF activity in cultured mammalian cells, and reduces diarrhea caused by enterotoxigenic Escherichia coli (ETEC) at an oral dosage of 15μg/mouse. Here, molecular docking was used to predict improvements in potency and solubility of new derivatives of compound 1 in inhibiting edema toxin (ET)-catalyzed stimulation of cyclic AMP production in murine monocyte-macrophage cells (RAW 264.7). Structure-activity relationship (SAR) analysis of the bioassay results for 22 compounds indicated positions important for activity. Several derivatives demonstrated superior pharmacological properties compared to our initial lead compound, and are promising candidates to treat anthrax infections and diarrheal diseases induced by toxin-producing bacteria.
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Affiliation(s)
- Deliang Chen
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, UTMB, Galveston, TX 77555-0857, USA
| | - Lili Ma
- Department of Chemistry, University of Houston. Houston, TX 77004, USA
| | | | - Jian Gao
- Mission Pharmacal Company, San Antonio, TX USA
| | - Jennifer Pawlik
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
| | | | | | - Johnny W. Peterson
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
| | | | - Catherine H. Schein
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, UTMB, Galveston, TX 77555-0857, USA
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
- Member, Institute for Translational Studies, UTMB
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50
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Grant BJ, Lukman S, Hocker HJ, Sayyah J, Brown JH, McCammon JA, Gorfe AA. Novel allosteric sites on Ras for lead generation. PLoS One 2011; 6:e25711. [PMID: 22046245 PMCID: PMC3201956 DOI: 10.1371/journal.pone.0025711] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 09/08/2011] [Indexed: 12/31/2022] Open
Abstract
Aberrant Ras activity is a hallmark of diverse cancers and developmental diseases. Unfortunately, conventional efforts to develop effective small molecule Ras inhibitors have met with limited success. We have developed a novel multi-level computational approach to discover potential inhibitors of previously uncharacterized allosteric sites. Our approach couples bioinformatics analysis, advanced molecular simulations, ensemble docking and initial experimental testing of potential inhibitors. Molecular dynamics simulation highlighted conserved allosteric coupling of the nucleotide-binding switch region with distal regions, including loop 7 and helix 5. Bioinformatics methods identified novel transient small molecule binding pockets close to these regions and in the vicinity of the conformationally responsive switch region. Candidate binders for these pockets were selected through ensemble docking of ZINC and NCI compound libraries. Finally, cell-based assays confirmed our hypothesis that the chosen binders can inhibit the downstream signaling activity of Ras. We thus propose that the predicted allosteric sites are viable targets for the development and optimization of new drugs.
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Affiliation(s)
- Barry J. Grant
- Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (BG); (SL); (AG)
| | - Suryani Lukman
- Bioinformatics Institute, Agency for Science, Technology and Research, Singapore
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
- * E-mail: (BG); (SL); (AG)
| | - Harrison J. Hocker
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Jaqueline Sayyah
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Joan Heller Brown
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - J. Andrew McCammon
- Department of Chemistry and Biochemistry, Center for Theoretical Biological Physics and Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, United States of America
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- * E-mail: (BG); (SL); (AG)
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