1
|
Nosek V, Míšek J. Sulfinamide Crossover Reaction. J Org Chem 2024; 89:7927-7932. [PMID: 38785122 PMCID: PMC11165587 DOI: 10.1021/acs.joc.4c00572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
This study unveils a new catalytic crossover reaction of sulfinamides. Leveraging mild acid catalysis, the reaction demonstrates a high tolerance to structural variations, yielding equimolar products across diverse sulfinamide substrates. Notably, small sulfinamide libraries can be selectively oxidized to sulfonamides, providing a new platform for ligand optimization and discovery in medicinal chemistry. This crossover chemotype provides a new tool for high-throughput experimentation in discovery chemistry.
Collapse
Affiliation(s)
- Vladimír Nosek
- Department of Organic Chemistry, Faculty
of Science, Charles University in Prague, Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Jiří Míšek
- Department of Organic Chemistry, Faculty
of Science, Charles University in Prague, Hlavova 2030/8, 12843 Prague 2, Czech Republic
| |
Collapse
|
2
|
Gabriel J, Höfner G, Wanner KT. Combination of MS Binding Assays and affinity selection mass spectrometry for screening of structurally homogenous libraries as exemplified for a focused oxime library addressing the neuronal GABA transporter 1. Eur J Med Chem 2020; 206:112598. [PMID: 32896797 DOI: 10.1016/j.ejmech.2020.112598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/09/2020] [Accepted: 06/16/2020] [Indexed: 11/30/2022]
Abstract
This study presents an efficient screening approach based on combination of mass spectrometry (MS) based binding assays (MS Binding Assays) and affinity selection mass spectrometry (ASMS) customized for screening of structurally homogeneous libraries sharing a common mass spectrometric fragmentation pattern. After reaction of a nipecotic acid derivative possessing a hydroxylamine functionality with aldehydes, the resulting oxime library was screened accordingly toward the GABA transporter subtype 1 (GAT1), a drug target for several neurological disorders. After assessing sublibraries' activities for inhibition of reporter ligand binding, hits in active ones were directly identified. This could be achieved by recording mass transitions for the reporter ligand as well as those predicted for the library components in a single LC-MS/MS run with a triple quadrupole mass spectrometer in the multiple reaction monitoring mode. Identification of hits with a predefined affinity could be reliably accomplished by calculation of IC50-values from specific binding concentrations of library constituents and reporter ligand. Application of this strategy revealed six hits, from which two of them were resynthesized for further biological evaluation. Thereby, the best one displayed a pKi of 7.38 in MS Binding Assays and a pIC50 of 6.82 in [3H]GABA uptake assays for GAT1.
Collapse
Affiliation(s)
- Jürgen Gabriel
- Faculty of Chemistry and Pharmacy, Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Georg Höfner
- Faculty of Chemistry and Pharmacy, Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Klaus T Wanner
- Faculty of Chemistry and Pharmacy, Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany.
| |
Collapse
|
3
|
Zaręba P, Gryzło B, Malawska K, Sałat K, Höfner GC, Nowaczyk A, Fijałkowski Ł, Rapacz A, Podkowa A, Furgała A, Żmudzki P, Wanner KT, Malawska B, Kulig K. Novel mouse GABA uptake inhibitors with enhanced inhibitory activity toward mGAT3/4 and their effect on pain threshold in mice. Eur J Med Chem 2020; 188:111920. [DOI: 10.1016/j.ejmech.2019.111920] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/16/2019] [Accepted: 11/27/2019] [Indexed: 12/12/2022]
|
4
|
Abstract
The transport of materials across membranes is a vital process for all aspects of cellular function, including growth, metabolism, and communication. Protein transporters are the molecular gates that control this movement and serve as key points of regulation for these processes, thus representing an attractive class of therapeutic targets. With more than 400 members, the solute carrier (SLC) membrane transport proteins are the largest family of transporters, yet, they are pharmacologically underexploited relative to other protein families and many of the available chemical tools possess suboptimal selectivity and efficacy. Fortuitously, there is increased interest in elucidating the physiological roles of SLCs as well as growing recognition of their therapeutic potential. This Perspective provides an overview of the SLC superfamily, including their biochemical and functional features, as well as their roles in various human diseases. In particular, we explore efforts and associated challenges toward drugging SLCs, as well as highlight opportunities for future drug discovery.
Collapse
Affiliation(s)
- Wesley Wei Wang
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Leandro Gallo
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Appaso Jadhav
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Richard Hawkins
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Christopher G Parker
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States.,Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| |
Collapse
|
5
|
Application of the concept of oxime library screening by mass spectrometry (MS) binding assays to pyrrolidine-3-carboxylic acid derivatives as potential inhibitors of γ-aminobutyric acid transporter 1 (GAT1). Bioorg Med Chem 2019; 27:2753-2763. [PMID: 31097402 DOI: 10.1016/j.bmc.2019.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/15/2019] [Accepted: 05/01/2019] [Indexed: 11/20/2022]
Abstract
In the present study, the concept of oxime library screening by MS Binding Assays was successfully extended to N-substituted lipophilic pyrrolidine-3-carboxylic acid derivatives in the pursuit of varying the amino acid motif in order to identify new inhibitors for GAT1 and to broaden structure-activity-relationships for this target, the most abundant GABA transporter in the central nervous system. For the screening, 28 different oxime sub-libraries were employed that were generated by simple condensation reaction of an excess of pyrrolidine-3-carboxylic acid derivatives carrying a hydroxylamine functionality with various sub-libraries each assembled of eight aldehydes with broadly varying chemical structures and functionalities. The compounds responsible for the activity of an oxime sub-library were identified by deconvolution experiments performed by employing single oximes. Binding affinities of the oxime hits were confirmed in full-scale competitive MS Binding Assays. Thereby, oxime derivatives with a 1,1'-biphenyl moiety were found as the first inhibitors of mGAT1 comprising a pyrrolidine-3-carboxylic acid motif with affinities in the submicromolar range.
Collapse
|
6
|
Hartman AM, Gierse RM, Hirsch AKH. Protein-Templated Dynamic Combinatorial Chemistry: Brief Overview and Experimental Protocol. European J Org Chem 2019; 2019:3581-3590. [PMID: 31680778 PMCID: PMC6813629 DOI: 10.1002/ejoc.201900327] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Indexed: 01/08/2023]
Abstract
Dynamic combinatorial chemistry (DCC) is a powerful tool to identify bioactive compounds. This efficient technique allows the target to select its own binders and circumvents the need for synthesis and biochemical evaluation of all individual derivatives. An ever-increasing number of publications report the use of DCC on biologically relevant target proteins. This minireview complements previous reviews by focusing on the experimental protocol and giving detailed examples of essential steps and factors that need to be considered, such as protein stability, buffer composition and cosolvents.
Collapse
Affiliation(s)
- Alwin M. Hartman
- Department of Drug Design and OptimizationHelmholtz Institute for Pharmaceutical Research Saarland (HIPS)Helmholtz Centre for Infection Research (HZI)Campus Building E8.166123SaarbrückenGermany
- Stratingh Institute for ChemistryHelmholtz Centre for Infection Research (HZI)University of GroningenNijenborgh 79747AG GroningenThe Netherlands
- Department of PharmacyMedicinal ChemistrySaarland UniversityCampus Building E8.166123SaarbrückenGermany
| | - Robin M. Gierse
- Department of Drug Design and OptimizationHelmholtz Institute for Pharmaceutical Research Saarland (HIPS)Helmholtz Centre for Infection Research (HZI)Campus Building E8.166123SaarbrückenGermany
- Stratingh Institute for ChemistryHelmholtz Centre for Infection Research (HZI)University of GroningenNijenborgh 79747AG GroningenThe Netherlands
- Department of PharmacyMedicinal ChemistrySaarland UniversityCampus Building E8.166123SaarbrückenGermany
| | - Anna K. H. Hirsch
- Department of Drug Design and OptimizationHelmholtz Institute for Pharmaceutical Research Saarland (HIPS)Helmholtz Centre for Infection Research (HZI)Campus Building E8.166123SaarbrückenGermany
- Stratingh Institute for ChemistryHelmholtz Centre for Infection Research (HZI)University of GroningenNijenborgh 79747AG GroningenThe Netherlands
- Department of PharmacyMedicinal ChemistrySaarland UniversityCampus Building E8.166123SaarbrückenGermany
| |
Collapse
|
7
|
Wu G, Zhao T, Kang D, Zhang J, Song Y, Namasivayam V, Kongsted J, Pannecouque C, De Clercq E, Poongavanam V, Liu X, Zhan P. Overview of Recent Strategic Advances in Medicinal Chemistry. J Med Chem 2019; 62:9375-9414. [PMID: 31050421 DOI: 10.1021/acs.jmedchem.9b00359] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introducing novel strategies, concepts, and technologies that speed up drug discovery and the drug development cycle is of great importance both in the highly competitive pharmaceutical industry as well as in academia. This Perspective aims to present a "big-picture" overview of recent strategic innovations in medicinal chemistry and drug discovery.
Collapse
Affiliation(s)
- Gaochan Wu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| | - Tong Zhao
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| | - Dongwei Kang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| | - Jian Zhang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| | - Yuning Song
- Department of Clinical Pharmacy , Qilu Hospital of Shandong University , 250012 Ji'nan , China
| | - Vigneshwaran Namasivayam
- Pharmaceutical Institute, Pharmaceutical Chemistry II , University of Bonn , 53121 Bonn , Germany
| | - Jacob Kongsted
- Department of Physics, Chemistry, and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Christophe Pannecouque
- Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy , K.U. Leuven , Herestraat 49 Postbus 1043 (09.A097) , B-3000 Leuven , Belgium
| | - Erik De Clercq
- Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy , K.U. Leuven , Herestraat 49 Postbus 1043 (09.A097) , B-3000 Leuven , Belgium
| | - Vasanthanathan Poongavanam
- Department of Physics, Chemistry, and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Xinyong Liu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| | - Peng Zhan
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences , Shandong University , 44 West Culture Road , 250012 Ji'nan , Shandong , P. R. China
| |
Collapse
|
8
|
Hauke TJ, Höfner G, Wanner KT. MS-Based Screening of 5-Substituted Nipecotic Acid Derived Hydrazone Libraries as Ligands of the GABA Transporter 1. ChemMedChem 2019; 14:583-593. [PMID: 30663849 DOI: 10.1002/cmdc.201800729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/09/2019] [Indexed: 11/09/2022]
Abstract
A screening of compound libraries based on nipecotic acid derivatives with lipophilic residues attached to the scarcely explored 5-position of the core structure was used for the search of new inhibitors of the γ-aminobutyric acid (GABA) transporter 1 (mGAT1). The generated compound libraries, which were based on hydrazone chemistry commonly used in dynamic combinatorial chemistry but rendered pseudostatic, were screened for their binding affinities toward mGAT1 by means of MS Binding Assays. With nipecotic acid derived hydrazone rac-16 h [rac-(3R,5S)-{5-[(E)-2-{[5-(2-phenylethynyl)thiophen-2-yl]methylidene}hydrazin-1-yl]piperidine-3-carboxylic acid}-sodium chloride (1/2)], one hit was found and evaluated displaying sub-micromolar potency (pKi =6.62±0.04) and a noncompetitive interaction mode at mGAT1. By bearing a 5-(2-phenylethynyl)thiophen-2-yl residue attached to the 5-position of nipecotic acid via a three-atom spacer, compound rac-16 h contains a structural moiety so far unprecedented for these kinds of bioactive molecules, and complements novel 5-substituted nipecotic acid derived ligands of mGAT1 revealed in a recently published screening campaign. This new class of ligands, with an inhibition mode distinct from that of benchmark mGAT1 inhibitors, could serve as research tools for investigations of mGAT1-mediated GABA transport.
Collapse
Affiliation(s)
- Tobias J Hauke
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Georg Höfner
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Klaus T Wanner
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| |
Collapse
|
9
|
Kern F, Wanner KT. Screening oxime libraries by means of mass spectrometry (MS) binding assays: Identification of new highly potent inhibitors to optimized inhibitors γ-aminobutyric acid transporter 1. Bioorg Med Chem 2019; 27:1232-1245. [PMID: 30777661 DOI: 10.1016/j.bmc.2019.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/07/2019] [Indexed: 11/26/2022]
Abstract
Generation and screening of oxime libraries by competitive MS Binding Assays represents a powerful tool for the identification of new compounds, with affinity to mGAT1, the most abundant plasma membrane bound GABA transporter in the CNS. By screening a guvacine derived oxime library, new potent inhibitors of mGAT1 had been revealed. In the present study, oxime libraries generated by reaction of a large excess of a rac-nipecotic acid derivative displaying a hydroxylamine functionality in which various aldehydes under suitable conditions, were examined for new potent inhibitors of mGAT1. The pKi values obtained of the best hits were compared with those of related compounds displaying a guvacine instead of a nipecotic acid subunit as hydrophilic moiety. Amongst the new compounds one of the most affine ligands of mGAT1 known so far (pKi = 8.55 ± 0.04) was found.
Collapse
Affiliation(s)
- Felix Kern
- Department Pharmacy - Center for Drug Research, Ludwig-Maximilians-University München, Butenandtstr. 7, 81377 Munich, Germany
| | - Klaus T Wanner
- Department Pharmacy - Center for Drug Research, Ludwig-Maximilians-University München, Butenandtstr. 7, 81377 Munich, Germany.
| |
Collapse
|
10
|
Hauke TJ, Höfner G, Wanner KT. Generation and screening of pseudostatic hydrazone libraries derived from 5-substituted nipecotic acid derivatives at the GABA transporter mGAT4. Bioorg Med Chem 2019; 27:144-152. [DOI: 10.1016/j.bmc.2018.11.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/29/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
|
11
|
Huber SK, Höfner G, Wanner KT. Identification of Pyrrolidine‐3‐acetic Acid Derived Oximes as Potent Inhibitors of γ‐Aminobutyric Acid Transporter 1 through Library Screening with MS Binding Assays. ChemMedChem 2018; 13:2488-2503. [DOI: 10.1002/cmdc.201800556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Simone K. Huber
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
| | - Georg Höfner
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
| | - Klaus T. Wanner
- Department of Pharmacy, Center of Drug ResearchLudwig Maximilians University of Munich Butenandtstr. 7 81377 Munich Germany
| |
Collapse
|
12
|
Hauke TJ, Wein T, Höfner G, Wanner KT. Novel Allosteric Ligands of γ-Aminobutyric Acid Transporter 1 (GAT1) by MS Based Screening of Pseudostatic Hydrazone Libraries. J Med Chem 2018; 61:10310-10332. [DOI: 10.1021/acs.jmedchem.8b01602] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Tobias J. Hauke
- Department of Pharmacy—Center of Drug Research, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
| | - Thomas Wein
- Department of Pharmacy—Center of Drug Research, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
| | - Georg Höfner
- Department of Pharmacy—Center of Drug Research, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
| | - Klaus T. Wanner
- Department of Pharmacy—Center of Drug Research, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
| |
Collapse
|
13
|
Monjas L, Swier LJYM, Setyawati I, Slotboom DJ, Hirsch AKH. Dynamic Combinatorial Chemistry to Identify Binders of ThiT, an S-Component of the Energy-Coupling Factor Transporter for Thiamine. ChemMedChem 2017; 12:1693-1696. [PMID: 28960943 PMCID: PMC5698757 DOI: 10.1002/cmdc.201700440] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/13/2017] [Indexed: 02/05/2023]
Abstract
We applied dynamic combinatorial chemistry (DCC) to identify ligands of ThiT, the S-component of the energy-coupling factor (ECF) transporter for thiamine in Lactococcus lactis. We used a pre-equilibrated dynamic combinatorial library (DCL) and saturation-transfer difference (STD) NMR spectroscopy to identify ligands of ThiT. This is the first report in which DCC is used for fragment growing to an ill-defined pocket, and one of the first reports for its application with an integral membrane protein as target.
Collapse
Affiliation(s)
- Leticia Monjas
- Stratingh Institute for ChemistryUniversity of GroningenNijenborgh 79747AGGroningenThe Netherlands
| | - Lotteke J. Y. M. Swier
- Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Inda Setyawati
- Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
- Biochemistry DepartmentBogor Agricultural UniversityBogorIndonesia
| | - Dirk J. Slotboom
- Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Anna K. H. Hirsch
- Stratingh Institute for ChemistryUniversity of GroningenNijenborgh 79747AGGroningenThe Netherlands
- Current address: Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) – Helmholtz Centre for Infection Research (HZI)Department of Drug Design and Optimization66123SaarbrückenGermany
- Department of Pharmacy, Medicinal ChemistrySaarland UniversityCampus Building E8.166123SaarbrückenGermany
| |
Collapse
|
14
|
Jaegle M, Wong EL, Tauber C, Nawrotzky E, Arkona C, Rademann J. Proteintemplat-gesteuerte Fragmentligationen - von der molekularen Erkennung zur Wirkstofffindung. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 129:7464-7485. [PMID: 32313319 PMCID: PMC7159557 DOI: 10.1002/ange.201610372] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/10/2017] [Indexed: 12/28/2022]
Abstract
AbstractProteintemplat‐gesteuerte Fragmentligationen sind ein neuartiges Konzept zur Unterstützung der Wirkstofffindung und können dazu beitragen, die Wirksamkeit von Proteinliganden zu verbessern. Es handelt sich dabei um chemische Reaktionen zwischen niedermolekularen Verbindungen (“Fragmenten”), die die Oberfläche eines Proteins als Reaktionsgefäß verwenden, um die Bildung eines Proteinliganden mit erhöhter Bindungsaffinität zu katalysieren. Die Methode nutzt die molekulare Erkennung kleiner reaktiver Fragmente durch die Proteine sowohl zur Assemblierung der Liganden als auch zur Identifizierung bioaktiver Fragmentkombinationen. Chemische Synthese und Bioassay werden dabei in einem Schritt vereint. Dieser Aufsatz diskutiert die biophysikalischen Grundlagen der reversiblen und irreversiblen Fragmentligationen und gibt einen Überblick über die Methoden, mit denen die durch das Proteintemplat gebildeten Ligationsprodukte detektiert werden können. Der chemische Reaktionsraum und aktuelle Anwendungen wie auch die Bedeutung dieses Konzeptes für die Wirkstofffindung werden erörtert.
Collapse
Affiliation(s)
- Mike Jaegle
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| | - Ee Lin Wong
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| | - Carolin Tauber
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| | - Eric Nawrotzky
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| | - Christoph Arkona
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| | - Jörg Rademann
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Straße 2+4Berlin14195Deutschland
| |
Collapse
|
15
|
Jaegle M, Wong EL, Tauber C, Nawrotzky E, Arkona C, Rademann J. Protein-Templated Fragment Ligations-From Molecular Recognition to Drug Discovery. Angew Chem Int Ed Engl 2017; 56:7358-7378. [PMID: 28117936 PMCID: PMC7159684 DOI: 10.1002/anie.201610372] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/10/2017] [Indexed: 12/14/2022]
Abstract
Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") utilizing a protein's surface as a reaction vessel to catalyze the formation of a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small-molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. In this way, chemical synthesis and bioassay are integrated in one single step. This Review discusses the biophysical basis of reversible and irreversible fragment ligations and gives an overview of the available methods to detect protein-templated ligation products. The chemical scope and recent applications as well as future potential of the concept in drug discovery are reviewed.
Collapse
Affiliation(s)
- Mike Jaegle
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| | - Ee Lin Wong
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| | - Carolin Tauber
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| | - Eric Nawrotzky
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| | - Christoph Arkona
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| | - Jörg Rademann
- Freie Universität BerlinMedicinal ChemistryKönigin-Luise-Strasse 2+4Berlin14195Germany
| |
Collapse
|
16
|
Khuri N, Zur AA, Wittwer MB, Lin L, Yee SW, Sali A, Giacomini KM. Computational Discovery and Experimental Validation of Inhibitors of the Human Intestinal Transporter OATP2B1. J Chem Inf Model 2017; 57:1402-1413. [PMID: 28562037 DOI: 10.1021/acs.jcim.6b00720] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Human organic anion transporters (OATPs) are vital for the uptake and efflux of drugs and endogenous compounds. Current identification of inhibitors of these transporters is based on experimental screening. Virtual screening remains a challenge due to a lack of experimental three-dimensional protein structures. Here, we describe a workflow to identify inhibitors of the OATP2B1 transporter in the DrugBank library of over 5,000 drugs and druglike molecules. OATP member 2B1 transporter is highly expressed in the intestine, where it participates in oral absorption of drugs. Predictions from a Random forest classifier, prioritized by docking against multiple comparative protein structure models of OATP2B1, indicated that 33 of the 5,000 compounds were putative inhibitors of OATP2B1. Ten predicted inhibitors that are prescription drugs were tested experimentally in cells overexpressing the OATP2B1 transporter. Three of these ten were validated as potent inhibitors of estrone-3-sulfate uptake (defined as more than 50% inhibition at 20 μM) and tested in multiple concentrations to determine exact IC50. The IC50 values of bicalutamide, ticagrelor, and meloxicam suggest that they might inhibit intestinal OATP2B1 at clinically relevant concentrations and therefore modulate the absorption of other concomitantly administered drugs.
Collapse
Affiliation(s)
- Natalia Khuri
- Bioengineering Department, Stanford University , Stanford, California 94305, United States
| | | | | | | | | | - Andrej Sali
- Department of Pharmaceutical Chemistry and California Institute of Quantitative Biosciences (QB3), University of California San Francisco , San Francisco, California 94158, United States
| | | |
Collapse
|
17
|
Eschweiler JD, Kerr R, Rabuck-Gibbons J, Ruotolo BT. Sizing Up Protein-Ligand Complexes: The Rise of Structural Mass Spectrometry Approaches in the Pharmaceutical Sciences. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2017; 10:25-44. [PMID: 28301749 DOI: 10.1146/annurev-anchem-061516-045414] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Capturing the dynamic interplay between proteins and their myriad interaction partners is critically important for advancing our understanding of almost every biochemical process and human disease. The importance of this general area has spawned many measurement methods capable of assaying such protein complexes, and the mass spectrometry-based structural biology methods described in this review form an important part of that analytical arsenal. Here, we survey the basic principles of such measurements, cover recent applications of the technology that have focused on protein-small-molecule complexes, and discuss the bright future awaiting this group of technologies.
Collapse
Affiliation(s)
| | - Richard Kerr
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109;
| | | | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109;
| |
Collapse
|
18
|
van der Vlag R, Hirsch A. Analytical Methods in Protein-Templated Dynamic Combinatorial Chemistry. COMPREHENSIVE SUPRAMOLECULAR CHEMISTRY II 2017. [PMCID: PMC7150222 DOI: 10.1016/b978-0-12-409547-2.12559-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
19
|
Protein-Directed Dynamic Combinatorial Chemistry: A Guide to Protein Ligand and Inhibitor Discovery. Molecules 2016; 21:molecules21070910. [PMID: 27438816 PMCID: PMC6273345 DOI: 10.3390/molecules21070910] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/04/2016] [Accepted: 07/08/2016] [Indexed: 01/16/2023] Open
Abstract
Protein-directed dynamic combinatorial chemistry is an emerging technique for efficient discovery of novel chemical structures for binding to a target protein. Typically, this method relies on a library of small molecules that react reversibly with each other to generate a combinatorial library. The components in the combinatorial library are at equilibrium with each other under thermodynamic control. When a protein is added to the equilibrium mixture, and if the protein interacts with any components of the combinatorial library, the position of the equilibrium will shift and those components that interact with the protein will be amplified, which can then be identified by a suitable biophysical technique. Such information is useful as a starting point to guide further organic synthesis of novel protein ligands and enzyme inhibitors. This review uses literature examples to discuss the practicalities of applying this method to inhibitor discovery, in particular, the set-up of the combinatorial library, the reversible reactions that may be employed, and the choice of detection methods to screen protein ligands from a mixture of reversibly forming molecules.
Collapse
|
20
|
Woods LA, Dolezal O, Ren B, Ryan JH, Peat TS, Poulsen SA. Native State Mass Spectrometry, Surface Plasmon Resonance, and X-ray Crystallography Correlate Strongly as a Fragment Screening Combination. J Med Chem 2016; 59:2192-204. [PMID: 26882437 DOI: 10.1021/acs.jmedchem.5b01940] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fragment-based drug discovery (FBDD) is contingent on the development of analytical methods to identify weak protein-fragment noncovalent interactions. Herein we have combined an underutilized fragment screening method, native state mass spectrometry, together with two proven and popular fragment screening methods, surface plasmon resonance and X-ray crystallography, in a fragment screening campaign against human carbonic anhydrase II (CA II). In an initial fragment screen against a 720-member fragment library (the "CSIRO Fragment Library") seven CA II binding fragments, including a selection of nonclassical CA II binding chemotypes, were identified. A further 70 compounds that comprised the initial hit chemotypes were subsequently sourced from the full CSIRO compound collection and screened. The fragment results were extremely well correlated across the three methods. Our findings demonstrate that there is a tremendous opportunity to apply native state mass spectrometry as a complementary fragment screening method to accelerate drug discovery.
Collapse
Affiliation(s)
- Lucy A Woods
- Griffith University , Eskitis Institute for Drug Discovery, Brisbane, Queensland Australia
| | - Olan Dolezal
- CSIRO Biomedical Manufacturing Program, Melbourne, Victoria Australia
| | - Bin Ren
- CSIRO Biomedical Manufacturing Program, Melbourne, Victoria Australia
| | - John H Ryan
- CSIRO Biomedical Manufacturing Program, Melbourne, Victoria Australia
| | - Thomas S Peat
- CSIRO Biomedical Manufacturing Program, Melbourne, Victoria Australia
| | - Sally-Ann Poulsen
- Griffith University , Eskitis Institute for Drug Discovery, Brisbane, Queensland Australia
| |
Collapse
|
21
|
Harnessing dynamic combinatorial chemistry in the search for new ligands for protein targets. Future Med Chem 2015; 7:2095-8. [DOI: 10.4155/fmc.15.146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
22
|
Tedesco D, Bertucci C. Induced circular dichroism as a tool to investigate the binding of drugs to carrier proteins: Classic approaches and new trends. J Pharm Biomed Anal 2015; 113:34-42. [PMID: 25769668 DOI: 10.1016/j.jpba.2015.02.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 10/24/2022]
Abstract
Induced circular dichroism (ICD) is a spectroscopic phenomenon that provides versatile and useful methods for characterizing the structural and dynamic properties of the binding of drugs to target proteins. The understanding of biorecognition processes at the molecular level is essential to discover and validate new pharmacological targets, and to design and develop new potent and selective drugs. The present article reviews the main applications of ICD to drug binding studies on serum carrier proteins, going from the classic approaches for the derivation of drug binding parameters and the identification of binding sites, to an overview of the emerging trends for the characterization of binding modes by means of quantum chemical (QC) techniques. The advantages and limits of the ICD methods for the determination of binding parameters are critically reviewed; the capability to investigate the binding interactions of drugs and metabolites to their target proteins is also underlined, as well as the possibility of characterizing the binding sites to obtain a complete picture of the binding mechanism and dynamics. The new applications of ICD methods to identify stereoselective binding modes of drug/protein complexes are then reviewed with relevant examples. The combined application of experimental ICD spectroscopy and QC calculations is shown to identify qualitatively the bound conformations of ligands to target proteins even in the absence of a detailed structure of the binding sites, either obtained from experimental X-ray crystallography and NMR measurements or from computational models of the complex.
Collapse
Affiliation(s)
- Daniele Tedesco
- Department of Pharmacy and Biotechnology, University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Carlo Bertucci
- Department of Pharmacy and Biotechnology, University of Bologna, via Belmeloro 6, 40126 Bologna, Italy.
| |
Collapse
|
23
|
Mondal M, Hirsch AKH. Dynamic combinatorial chemistry: a tool to facilitate the identification of inhibitors for protein targets. Chem Soc Rev 2015; 44:2455-88. [DOI: 10.1039/c4cs00493k] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dynamic combinatorial chemistry enables efficient identification of protein binder(s) from a library of interconverting compounds. The library responds to the addition of the target by amplifying the strongest binder.
Collapse
Affiliation(s)
- Milon Mondal
- Stratingh Institute for Chemistry
- University of Groningen
- 9747 AG Groningen
- The Netherlands
| | - Anna K. H. Hirsch
- Stratingh Institute for Chemistry
- University of Groningen
- 9747 AG Groningen
- The Netherlands
| |
Collapse
|
24
|
Development and validation of an LC-ESI-MS/MS method for the triple reuptake inhibitor indatraline enabling its quantification in MS Binding Assays. Anal Bioanal Chem 2014; 407:471-85. [DOI: 10.1007/s00216-014-8312-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/29/2014] [Accepted: 10/31/2014] [Indexed: 10/24/2022]
|
25
|
Kern FT, Wanner KT. Generation and Screening of Oxime Libraries Addressing the Neuronal GABA Transporter GAT1. ChemMedChem 2014; 10:396-410. [DOI: 10.1002/cmdc.201402376] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Indexed: 01/03/2023]
|
26
|
Herrmann A. Dynamic combinatorial/covalent chemistry: a tool to read, generate and modulate the bioactivity of compounds and compound mixtures. Chem Soc Rev 2014; 43:1899-933. [PMID: 24296754 DOI: 10.1039/c3cs60336a] [Citation(s) in RCA: 281] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Reversible covalent bond formation under thermodynamic control adds reactivity to self-assembled supramolecular systems, and is therefore an ideal tool to assess complexity of chemical and biological systems. Dynamic combinatorial/covalent chemistry (DCC) has been used to read structural information by selectively assembling receptors with the optimum molecular fit around a given template from a mixture of reversibly reacting building blocks. This technique allows access to efficient sensing devices and the generation of new biomolecules, such as small molecule receptor binders for drug discovery, but also larger biomimetic polymers and macromolecules with particular three-dimensional structural architectures. Adding a kinetic factor to a thermodynamically controlled equilibrium results in dynamic resolution and in self-sorting and self-replicating systems, all of which are of major importance in biological systems. Furthermore, the temporary modification of bioactive compounds by reversible combinatorial/covalent derivatisation allows control of their release and facilitates their transport across amphiphilic self-assembled systems such as artificial membranes or cell walls. The goal of this review is to give a conceptual overview of how the impact of DCC on supramolecular assemblies at different levels can allow us to understand, predict and modulate the complexity of biological systems.
Collapse
Affiliation(s)
- Andreas Herrmann
- Firmenich SA, Division Recherche et Développement, Route des Jeunes 1, B. P. 239, CH-1211 Genève 8, Switzerland.
| |
Collapse
|
27
|
Kempson SA, Zhou Y, Danbolt NC. The betaine/GABA transporter and betaine: roles in brain, kidney, and liver. Front Physiol 2014; 5:159. [PMID: 24795654 PMCID: PMC4006062 DOI: 10.3389/fphys.2014.00159] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/04/2014] [Indexed: 12/18/2022] Open
Abstract
The physiological roles of the betaine/GABA transporter (BGT1; slc6a12) are still being debated. BGT1 is a member of the solute carrier family 6 (the neurotransmitter, sodium symporter transporter family) and mediates cellular uptake of betaine and GABA in a sodium- and chloride-dependent process. Most of the studies of BGT1 concern its function and regulation in the kidney medulla where its role is best understood. The conditions here are hostile due to hyperosmolarity and significant concentrations of NH4Cl and urea. To withstand the hyperosmolarity, cells trigger osmotic adaptation, involving concentration of a transcriptional factor TonEBP/NFAT5 in the nucleus, and accumulate betaine and other osmolytes. Data from renal cells in culture, primarily MDCK, revealed that transcriptional regulation of BGT1 by TonEBP/NFAT5 is relatively slow. To allow more acute control of the abundance of BGT1 protein in the plasma membrane, there is also post-translation regulation of BGT1 protein trafficking which is dependent on intracellular calcium and ATP. Further, betaine may be important in liver metabolism as a methyl donor. In fact, in the mouse the liver is the organ with the highest content of BGT1. Hepatocytes express high levels of both BGT1 and the only enzyme that can metabolize betaine, namely betaine:homocysteine –S-methyltransferase (BHMT1). The BHMT1 enzyme removes a methyl group from betaine and transfers it to homocysteine, a potential risk factor for cardiovascular disease. Finally, BGT1 has been proposed to play a role in controlling brain excitability and thereby represents a target for anticonvulsive drug development. The latter hypothesis is controversial due to very low expression levels of BGT1 relative to other GABA transporters in brain, and also the primary location of BGT1 at the surface of the brain in the leptomeninges. These issues are discussed in detail.
Collapse
Affiliation(s)
- Stephen A Kempson
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine Indianapolis, IN, USA
| | - Yun Zhou
- Department of Anatomy, Centre of Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| | - Niels C Danbolt
- Department of Anatomy, Centre of Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| |
Collapse
|
28
|
Sindelar M, Lutz TA, Petrera M, Wanner KT. Focused Pseudostatic Hydrazone Libraries Screened by Mass Spectrometry Binding Assay: Optimizing Affinities toward γ-Aminobutyric Acid Transporter 1. J Med Chem 2013; 56:1323-40. [DOI: 10.1021/jm301800j] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Miriam Sindelar
- Center for Drug Research, Department
of Pharmacy, Ludwig Maximilians University at Munich, Butenandtstrasse
9-13, D-81377 Munich, Germany
| | - Toni A. Lutz
- Center for Drug Research, Department
of Pharmacy, Ludwig Maximilians University at Munich, Butenandtstrasse
9-13, D-81377 Munich, Germany
| | - Marilena Petrera
- Center for Drug Research, Department
of Pharmacy, Ludwig Maximilians University at Munich, Butenandtstrasse
9-13, D-81377 Munich, Germany
| | - Klaus T. Wanner
- Center for Drug Research, Department
of Pharmacy, Ludwig Maximilians University at Munich, Butenandtstrasse
9-13, D-81377 Munich, Germany
| |
Collapse
|
29
|
Abstract
The mammalian genome contains four genes encoding GABA transporters (GAT1, slc6a1; GAT2, slc6a13; GAT3, slc6a11; BGT1, slc6a12) and five glutamate transporter genes (EAAT1, slc1a3; EAAT2, slc1a2; EAAT3, slc1a1; EAAT4, slc1a6; EAAT5, slc1a7). These transporters keep the extracellular levels of GABA and excitatory amino acids low and provide amino acids for metabolic purposes. The various transporters have different properties both with respect to their transport functions and with respect to their ability to act as ion channels. Further, they are differentially regulated. To understand the physiological roles of the individual transporter subtypes, it is necessary to obtain information on their distributions and expression levels. Quantitative data are important as the functional capacity is limited by the number of transporter molecules. The most important and most abundant transporters for removal of transmitter glutamate in the brain are EAAT2 (GLT-1) and EAAT1 (GLAST), while GAT1 and GAT3 are the major GABA transporters in the brain. EAAT3 (EAAC1) does not appear to play a role in signal transduction, but plays other roles. Due to their high uncoupled anion conductance, EAAT4 and EAAT5 seem to be acting more like inhibitory glutamate receptors than as glutamate transporters. GAT2 and BGT1 are primarily expressed in the liver and kidney, but are also found in the leptomeninges, while the levels in brain tissue proper are too low to have any impact on GABA removal, at least in normal young adult mice. The present review will provide summary of what is currently known and will also discuss some methodological pitfalls.
Collapse
Affiliation(s)
- Yun Zhou
- The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Niels Christian Danbolt
- The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- *Correspondence: Niels Christian Danbolt, The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, P.O. Box 1105 Blindern, Oslo N-0317, Norway e-mail:
| |
Collapse
|
30
|
Abstract
Native state mass spectrometry (MS) has been recognised as a rapid, sensitive, and high throughput method to directly investigate protein-ligand interactions for some time, however there are few examples reporting this approach as a screening method to identify relevant protein–fragment interactions in fragment-based drug discovery (FBDD). In this paper an overview of native state MS will be presented, highlighting the attractive properties of this method within the context of fragment screening applications. A summary of published examples using MS for fragment screening will be described and reflection on the outlook for the future adoption and implementation of native state MS as a complementary fragment screening method will be presented.
Collapse
|