1
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Bahls B, Aljnadi IM, Emídio R, Mendes E, Paulo A. G-Quadruplexes in c-MYC Promoter as Targets for Cancer Therapy. Biomedicines 2023; 11:biomedicines11030969. [PMID: 36979947 PMCID: PMC10046398 DOI: 10.3390/biomedicines11030969] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/09/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Cancer is a societal burden demanding innovative approaches. A major problem with the conventional chemotherapeutic agents is their strong toxicity and other side effects due to their poor selectivity. Uncontrolled proliferation of cancer cells is due to mutations, deletions, or amplifications in genes (oncogenes) encoding for proteins that regulate cell growth and division, such as transcription factors, for example, c-MYC. The direct targeting of the c-MYC protein has been attempted but so far unsuccessfully, as it lacks a definite binding site for the modulators. Meanwhile, another approach has been explored since the discovery that G-quadruplex secondary DNA structures formed in the guanine-rich sequences of the c-MYC promoter region can downregulate the transcription of this oncogene. Here, we will overview the major achievements made in the last decades towards the discovery of a new class of anticancer drugs targeting G-quadruplexes in the c-MYC promoter of cancer cells.
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Affiliation(s)
- Bárbara Bahls
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Israa M Aljnadi
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Rita Emídio
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Eduarda Mendes
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Alexandra Paulo
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
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2
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Vianney YM, Weisz K. High-affinity binding at quadruplex-duplex junctions: rather the rule than the exception. Nucleic Acids Res 2022; 50:11948-11964. [PMID: 36416262 PMCID: PMC9723630 DOI: 10.1093/nar/gkac1088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 11/24/2022] Open
Abstract
Quadruplex-duplex (Q-D) junctions constitute unique structural motifs in genomic sequences. Through comprehensive calorimetric as well as high-resolution NMR structural studies, Q-D junctions with a hairpin-type snapback loop coaxially stacked onto an outer G-tetrad were identified to be most effective binding sites for various polycyclic quadruplex ligands. The Q-D interface is readily recognized by intercalation of the ligand aromatic core structure between G-tetrad and the neighboring base pair. Based on the thermodynamic and structural data, guidelines for the design of ligands with enhanced selectivity towards a Q-D interface emerge. Whereas intercalation at Q-D junctions mostly outcompete stacking at the quadruplex free outer tetrad or intercalation between duplex base pairs to varying degrees, ligand side chains considerably contribute to the selectivity for a Q-D target over other binding sites. In contrast to common perceptions, an appended side chain that additionally interacts within the duplex minor groove may confer only poor selectivity. Rather, the Q-D selectivity is suggested to benefit from an extension of the side chain towards the exposed part of the G-tetrad at the junction. The presented results will support the design of selective high-affinity binding ligands for targeting Q-D interfaces in medicinal but also technological applications.
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Affiliation(s)
- Yoanes Maria Vianney
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, D-17489 Greifswald, Germany
| | - Klaus Weisz
- To whom correspondence should be addressed. Tel: +49 3834 420 4426; Fax: +49 3834 420 4427;
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3
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Kumar S, Pany SPP, Sudhakar S, Singh SB, Todankar CS, Pradeepkumar PI. Targeting Parallel Topology of G-Quadruplex Structures by Indole- Fused Quindoline Scaffolds. Biochemistry 2022; 61:2546-2559. [DOI: 10.1021/acs.biochem.2c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Satendra Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | | | - Sruthi Sudhakar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - Sushma B. Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - Chaitra S. Todankar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - P. I. Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
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4
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Kang Y, Wei C. A stilbene derivative as dual-channel fluorescent probe for mitochondrial G-quadruplex DNA in living cells. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 278:121316. [PMID: 35569198 DOI: 10.1016/j.saa.2022.121316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/15/2022] [Accepted: 04/24/2022] [Indexed: 06/15/2023]
Abstract
G-quadruplex DNA has attracted the widespread attention as a novel target of anticancer strategy. Herein, two novel stilbene derivatives 2a and 2b were designed and synthesized under mild reaction conditions, and their interactions with G-quadruplex DNA, cytotoxicity, and distribution in living cells were investigated in detail. Both compounds display a low cytotoxicity and the higher affinity to G-quadruplex DNA than to the other secondary structures, including duplex, single-stranded and i-motif DNA, moreover, the affinity of 2b with m-allyl pyridine salt group to G-quadruplex DNA is about 10-fold stronger than that of 2a with p-allyl pyridine salt group. The interactions of the compounds with the promoter G-quadruplexes are enthalpy-driven by an ITC assay. 2a and 2b not only stabilize the G-quadruplex structure but also induce the G-rich sequences (bcl-2, HRCC and KSS) to fold into the mixed-type G-quadruplex in Na+/K+ free Tris-HCl buffer at pH 7.0, and 2b presents the higher stabilization to G-quadruplex than 2a by a FRET-melting assay. 2b presents a dual-emission at 508 and 600 nm and gives a turn-on and stronger and more sensitive fluorescence response over 2a to the promoter (bcl-2, c-kit 2 and c-myc) and mitochondrial (HRCC and KSS) G-quadruplex DNA at both emission wavelengths, moreover, the peak at 508 nm is blue-shifted to 466 nm after binding to DNA. The blue and red dual-channel CLSM images indicate that 2b is mainly distributed in the mitochondrion of living HepG2 cells. The results show that 2b is a potential dual-channel fluorescent probe for mitochondrial G-quadruplex DNA in living cells.
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Affiliation(s)
- Yongqiang Kang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China
| | - Chunying Wei
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China.
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5
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Biver T. Discriminating between Parallel, Anti-Parallel and Hybrid G-Quadruplexes: Mechanistic Details on Their Binding to Small Molecules. Molecules 2022; 27:molecules27134165. [PMID: 35807410 PMCID: PMC9268745 DOI: 10.3390/molecules27134165] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 12/04/2022] Open
Abstract
G-quadruplexes (G4) are now extensively recognised as a peculiar non-canonical DNA geometry that plays a prime importance role in processes of biological relevance whose number is increasing continuously. The same is true for the less-studied RNA G4 counterpart. G4s are stable structures; however, their geometrical parameters may be finely tuned not only by the presence of particular sequences of nucleotides but also by the salt content of the medium or by a small molecule that may act as a peculiar topology inducer. As far as the interest in G4s increases and our knowledge of these species deepens, researchers do not only verify the G4s binding by small molecules and the subsequent G4 stabilisation. The most innovative studies now aim to elucidate the mechanistic details of the interaction and the ability of a target species (drug) to bind only to a peculiar G4 geometry. In this focused review, we survey the advances in the studies of the binding of small molecules of medical interest to G4s, with particular attention to the ability of these species to bind differently (intercalation, lateral binding or sitting atop) to different G4 topologies (parallel, anti-parallel or hybrid structures). Some species, given the very high affinity with some peculiar G4 topology, can first bind to a less favourable geometry and then induce its conversion. This aspect is also considered.
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Affiliation(s)
- Tarita Biver
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
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6
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Mendes E, Bahls B, Aljnadi IM, Paulo A. Indoloquinolines as scaffolds for the design of potent G-quadruplex ligands. Bioorg Med Chem Lett 2022; 72:128862. [PMID: 35716866 DOI: 10.1016/j.bmcl.2022.128862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 11/19/2022]
Abstract
Indoloquinolines are natural alkaloids with known affinity to DNA and antiproliferative activity against bacteria, parasites, and cancer cells. Due to their non-chiral skeleton, their total synthesis is easy to achieve and throughout the years, many derivatives have been studied for their potential as drugs. Herein we review the indoloquinolines and bioisosters that have been designed, synthesised, and evaluated for their selective binding to G-quadruplex nucleic acid structures, as well as the reported effects in cancer cells. The data collected so far strongly suggest that indoloquinolines are good scaffolds for the development of drugs and probes targeting the G-quadruplex structures, but they also show that this scaffold is still underexplored.
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Affiliation(s)
- Eduarda Mendes
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Av. Prof. Gama Pinto, Lisbon 1649-003, Portugal
| | - Bárbara Bahls
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Av. Prof. Gama Pinto, Lisbon 1649-003, Portugal
| | - Israa M Aljnadi
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Av. Prof. Gama Pinto, Lisbon 1649-003, Portugal
| | - Alexandra Paulo
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Av. Prof. Gama Pinto, Lisbon 1649-003, Portugal.
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7
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Kang Y, Wei C. Highly selective turn-on red fluorescence probes for visualization of the G-quadruplexes DNA in living cells. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120518. [PMID: 34700155 DOI: 10.1016/j.saa.2021.120518] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Studies on small molecule fluorescent probes for detecting G-quadruplexes DNA have bring about an extensive attention in recent years. In this paper, we designed and synthesized three benzothiazole derivatives named 2a-2c under moderate reaction conditions and investigated their interactions with DNA (single-stranded, duplex, i-motif and G-quadruplex) and distribution in living cell. Three compounds present a large Stokes shift (∼90 nm) and a weak red fluorescence emission, and they exhibit a good selectivity and sensitive turn-on fluorescence response for the promoter G-quadruplex DNA (bcl-2, c-myc and c-kit 2) and mitochondria G-quadruplex (KSS). The affinity of 2a and 2b with N-alkyl side chain group to DNA is stronger than that of 2c with an anion group, therefore, they also increase the stability of the G-quadruplex structure. 2b induces the conformational change of both bcl-2 and KSS G-quadruplexes, while all compounds induce the folding of bcl-2 from the coiled structure to the hybrid G-qrudruplex. Three compounds interact with the G-quadruplex DNA mainly by end-stacking mode. Furthermore, MTT assays and confocal fluorescence images show that these compounds can enter the living HepG2 cells with low cytotoxicity. 2a-2c are mainly located in the mitochondrion and interacted with mitochondria G-quadruplex DNA, while only weak fluorescence can be found in cell nucleus. In a word, 2a-2c can be implied in image of G-quadruplex DNA in living cells.
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Affiliation(s)
- Yongqiang Kang
- Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China
| | - Chunying Wei
- Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China.
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8
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Kang Y, Wei C. Crescent‐shaped carbazole derivatives as light‐up fluorescence probes for G‐quadruplex DNA and live cell imaging. Chem Biodivers 2022; 19:e202101030. [DOI: 10.1002/cbdv.202101030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/28/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Yongqiang Kang
- Shanxi University Institute of Molecular Science 92 Wucheng Road Taiyuan CHINA
| | - Chunying Wei
- Shanxi University Institute of Molecular Science No.92 Road Wucheng 030006 Taiyuan CHINA
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9
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Sun XS, Diao XY, Dong XQ, Wang CJ. Base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction: efficient access to δ-carboline derivatives. Chem Sci 2022; 13:10448-10454. [PMID: 36277643 PMCID: PMC9473522 DOI: 10.1039/d2sc03166c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/13/2022] [Indexed: 11/30/2022] Open
Abstract
A serendipitous and highly efficient approach for the construction of a variety of δ-carboline derivatives was developed through base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction of N-2,2,2-trifluoroethylisatin ketoimine esters with alkynes in good to high yields with excellent regio-/chemoselectivity control. Moreover, a reasonable reaction pathway was proposed, which was in accordance with the prepared reaction intermediate and control experiment results. The δ-carboline product could be easily converted into a new chiral Py-box-type ligand through simple synthetic transformations. This salient strategy featured the advantages of metal-free conditions, excellent regio-/chemoselectivity, good to high yields, and outstanding substrate tolerance. Importantly, the potential application of these fascinating δ-carboline derivative products is well demonstrated in the recognition of ferric ions. A serendipitous and efficient approach to access various δ-carbolines was developed through base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction in good to high yields with excellent regio/chemoselectivity.![]()
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Affiliation(s)
- Xi-Shang Sun
- College of Chemistry and Molecular Sciences, Engineering Research Center of Organosilicon Compounds & Materials, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Xin-Yu Diao
- College of Chemistry and Molecular Sciences, Engineering Research Center of Organosilicon Compounds & Materials, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Xiu-Qin Dong
- College of Chemistry and Molecular Sciences, Engineering Research Center of Organosilicon Compounds & Materials, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Chun-Jiang Wang
- College of Chemistry and Molecular Sciences, Engineering Research Center of Organosilicon Compounds & Materials, Wuhan University, Wuhan, Hubei, 430072, P. R. China
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, 300071, P. R. China
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10
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Vianney YM, Weisz K. Indoloquinoline Ligands Favor Intercalation at Quadruplex-Duplex Interfaces. Chemistry 2021; 28:e202103718. [PMID: 34905232 PMCID: PMC9303235 DOI: 10.1002/chem.202103718] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Indexed: 11/30/2022]
Abstract
Quadruplex‐duplex (Q‐D) junctions are increasingly considered promising targets for medicinal and technological applications. Here, a Q‐D hybrid with a hairpin‐type snapback loop coaxially stacked onto the quadruplex 3’‐outer tetrad was designed and employed as a target structure for the indoloquinoline ligand SYUIQ‐5. NMR spectral analysis demonstrated high‐affinity binding of the ligand at the quadruplex‐duplex interface with association constants determined by isothermal titration calorimetry of about 107 M−1 and large exothermicities ΔH° of −14 kcal/mol in a 120 mM K+ buffer at 40 °C. Determination of the ligand‐bound hybrid structure revealed intercalation of SYUIQ‐5 between 3’‐outer tetrad and the neighboring CG base pair, maximizing π–π stacking as well as electrostatic interactions with guanine carbonyl groups in close vicinity to the positively charged protonated quinoline nitrogen of the tetracyclic indoloquinoline. Exhibiting considerable flexibility, the SYUIQ‐5 sidechain resides in the duplex minor groove. Based on comparative binding studies with the non‐substituted N5‐methylated indoloquinoline cryptolepine, the sidechain is suggested to confer additional affinity and to fix the alignment of the intercalated indoloquinoline aromatic core. However, selectivity for the Q‐D junction mostly relies on the geometry and charge distribution of the indoloquinoline ring system. The presented results are expected to provide valuable guidelines for the design of ligands specifically targeting Q‐D interfaces.
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Affiliation(s)
- Yoanes Maria Vianney
- Universität Greifswald Mathematisch-Naturwissenschaftliche Fakultät: Universitat Greifswald Mathematisch-Naturwissenschaftliche Fakultat, Institut für Biochemie, Felix-Hausdorff-Str. 4, 17489, Greifswald, GERMANY
| | - Klaus Weisz
- Universität Greifswald, Institut für Biochemie, Felix-Hausdorff-Str. 4, 17487, Greifswald, GERMANY
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11
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Dickerhoff J, Brundridge N, McLuckey SA, Yang D. Berberine Molecular Recognition of the Parallel MYC G-Quadruplex in Solution. J Med Chem 2021; 64:16205-16212. [PMID: 34677968 PMCID: PMC8614230 DOI: 10.1021/acs.jmedchem.1c01508] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The medicinal natural product berberine is one of the most actively studied and pursued G-quadruplex (G4)-ligands. The major G-quadruplex formed in the promoter region of the MYC oncogene (MycG4) is an attractive drug target and a prominent example and model structure for parallel G-quadruplexes. G4-targeted berberine derivatives have been actively developed; however, the analogue design was based on a previous crystal structure in which berberine binds as a dimer to a parallel G-quadruplex. Herein, we show that in solution, the binding mode and stoichiometry of berberine are substantially different from the crystal structure: berberine binds as a monomer to MycG4 using a base-recruitment mechanism with a reversed orientation in that the positively charged convex side is actually positioned above the tetrad center. Our structure provides a physiologically relevant basis for the future structure-based rational design of G4-targeted berberine derivatives, and this study demonstrates that it is crucial to validate the ligand-DNA interactions.
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Affiliation(s)
- Jonathan Dickerhoff
- Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Avenue, West Lafayette, Indiana 47904, United States
| | - Nicole Brundridge
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Danzhou Yang
- Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Avenue, West Lafayette, Indiana 47904, United States
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
- Purdue Center for Cancer Research, and Purdue Institute for Drug Discovery, West Lafayette, Indiana 47907, United States
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12
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Macii F, Cupellini L, Stifano M, Santolaya J, Pérez-Arnaiz C, Pucci A, Barone G, García B, Busto N, Biver T. Combined spectroscopic and theoretical analysis of the binding of a water-soluble perylene diimide to DNA/RNA polynucleotides and G-quadruplexes. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 260:119914. [PMID: 34015745 DOI: 10.1016/j.saa.2021.119914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/23/2021] [Accepted: 05/02/2021] [Indexed: 06/12/2023]
Abstract
We present here a combined spectroscopic and theoretical analysis of the binding of N,N'-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylenetetracarboxylic acid diimide dichloride (PZPERY) to different biosubstrates. Absorbance titrations and circular dichroism experiments, melting studies and isothermal calorimetry (ITC) titrations reveal a picture where the binding to natural double-stranded DNA is very different from that to double and triple-stranded RNAs (poly(A)∙poly(U) and poly(U)∙poly(A)⁎poly(U)). As confirmed also by the structural and energetic details clarified by density functional theory (DFT) calculations, intercalation occurs for DNA, with a process driven by the combination of aggregates disruption and monomers intercalation. Oppositely, for RNAs, no intercalation but groove binding with the formation of supramolecular aggregates is observed. Among all the tested biosubstrates, the affinity of PZPERY towards DNA G-quadruplexes (G4) is the greatest one with a preference for human telomeric G4s. Focusing on hybrid G4 forms, either sitting-atop ("tetrad-parallel") or lateral ("groove-parallel") binding modes were considered in the discussion of the experimental results and molecular dynamics (MD) simulations. Both turned out to be possible concurrently, in agreement also with the experimental binding stoichiometries higher than 2:1.
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Affiliation(s)
- Francesca Macii
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Lorenzo Cupellini
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Mariassunta Stifano
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Javier Santolaya
- Department of Chemistry, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain
| | - Cristina Pérez-Arnaiz
- Department of Chemistry, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain
| | - Andrea Pucci
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Giampaolo Barone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze Ed. 17, 90128 Palermo, Italy
| | - Begoña García
- Department of Chemistry, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain
| | - Natalia Busto
- Department of Chemistry, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
| | - Tarita Biver
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy; Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy.
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13
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Nandy A, Shekhar S, Paul BK, Mukherjee S. Exploring the Nucleobase-Specific Hydrophobic Interaction of Cryptolepine Hydrate with RNA and Its Subsequent Sequestration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:11176-11187. [PMID: 34499515 DOI: 10.1021/acs.langmuir.1c02123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The study of the interactions of drug molecules with genetic materials plays a key role underlying the development of new drugs for many life-threatening diseases in pharmaceutical industries. Understanding their fundamental base-specific and/or groove-binding interaction is crucial to target the genetic material with an external drug, which can pave the way to curing diseases related to the genetic material. Here, we studied the interaction of cryptolepine hydrate (CRYP) with RNA under physiological conditions knowing the antimalarial and anticancer activities of the drug. Our experiments explicitly demonstrate that CRYP interacts with the guanine- and adenine-rich region within the RNA duplex. The pivotal role of the hydrophobic interaction governing the interaction is substantiated by temperature-dependent isothermal titration calorimetry experiments and spectroscopic studies. Circular dichroism study underpins a principally intercalative mode of binding of CRYP with RNA. This interaction is found to be drastically affected in the presence of magnesium salt, which has a strong propensity to coordinate with RNA nucleobases, which can in turn modulate the interaction of the drug with RNA. The temperature-dependent calorimetric results substantiate the occurrence of entropy-enthalpy compensation, which enabled us to rule out the possibility of groove binding of the drug with RNA. Furthermore, our results also show the application of host-guest chemistry in sequestering the RNA-bound drug, which is crucial to the development of safer therapeutic applications.
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Affiliation(s)
- Atanu Nandy
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Shashi Shekhar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Bijan K Paul
- Department of Chemistry, Mahadevananda Mahavidyalaya, Barrackpore, Kolkata 700120, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
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14
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Santos T, Salgado GF, Cabrita EJ, Cruz C. G-Quadruplexes and Their Ligands: Biophysical Methods to Unravel G-Quadruplex/Ligand Interactions. Pharmaceuticals (Basel) 2021; 14:769. [PMID: 34451866 PMCID: PMC8401999 DOI: 10.3390/ph14080769] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/31/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022] Open
Abstract
Progress in the design of G-quadruplex (G4) binding ligands relies on the availability of approaches that assess the binding mode and nature of the interactions between G4 forming sequences and their putative ligands. The experimental approaches used to characterize G4/ligand interactions can be categorized into structure-based methods (circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography), affinity and apparent affinity-based methods (surface plasmon resonance (SPR), isothermal titration calorimetry (ITC) and mass spectrometry (MS)), and high-throughput methods (fluorescence resonance energy transfer (FRET)-melting, G4-fluorescent intercalator displacement assay (G4-FID), affinity chromatography and microarrays. Each method has unique advantages and drawbacks, which makes it essential to select the ideal strategies for the biological question being addressed. The structural- and affinity and apparent affinity-based methods are in several cases complex and/or time-consuming and can be combined with fast and cheap high-throughput approaches to improve the design and development of new potential G4 ligands. In recent years, the joint use of these techniques permitted the discovery of a huge number of G4 ligands investigated for diagnostic and therapeutic purposes. Overall, this review article highlights in detail the most commonly used approaches to characterize the G4/ligand interactions, as well as the applications and types of information that can be obtained from the use of each technique.
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Affiliation(s)
- Tiago Santos
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal;
| | - Gilmar F. Salgado
- ARNA Laboratory, Université de Bordeaux, Inserm U1212, CNRS UMR 5320, IECB, 33607 Pessac, France;
| | - Eurico J. Cabrita
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal;
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
| | - Carla Cruz
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal;
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15
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Mohr S, Jana J, Vianney YM, Weisz K. Expanding the Topological Landscape by a G-Column Flip of a Parallel G-Quadruplex. Chemistry 2021; 27:10437-10447. [PMID: 33955615 PMCID: PMC8361731 DOI: 10.1002/chem.202101181] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 01/14/2023]
Abstract
Canonical G‐quadruplexes can adopt a variety of different topologies depending on the arrangement of propeller, lateral, or diagonal loops connecting the four G‐columns. A novel intramolecular G‐quadruplex structure is derived through inversion of the last G‐tract of a three‐layered parallel fold, associated with the transition of a single propeller into a lateral loop. The resulting (3+1) hybrid fold features three syn⋅anti⋅anti⋅anti G‐tetrads with a 3’‐terminal all‐syn G‐column. Although the ability of forming a duplex stem‐loop between G‐tracts seems beneficial for a propeller‐to‐lateral loop rearrangement, unmodified G‐rich sequences resist folding into the new (3+1) topology. However, refolding can be driven by the incorporation of syn‐favoring guanosine analogues into positions of the fourth G‐stretch. The presented hybrid‐type G‐quadruplex structure as determined by NMR spectroscopy may provide for an additional scaffold in quadruplex‐based technologies.
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Affiliation(s)
- Swantje Mohr
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Jagannath Jana
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Yoanes Maria Vianney
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
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16
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Busto N, Carrión MC, Montanaro S, Díaz de Greñu B, Biver T, Jalón FA, Manzano BR, García B. Targeting G-quadruplex structures with Zn(II) terpyridine derivatives: a SAR study. Dalton Trans 2021; 49:13372-13385. [PMID: 32955070 DOI: 10.1039/d0dt02125c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Based on the ability of terpyridines to react with G-quadruplex DNA (G4) structures along with the interest aroused by Zn as an essential metal centre in many biological processes, we have synthesized and characterized six Zn chloride or nitrate complexes containing terpyridine ligands with different 4'-substituents. In addition, we have studied their interaction with G4 and their cytotoxicity. Our experimental results revealed that the leaving group exerts a strong influence on the cytotoxicity, since the complexes bearing chloride were more cytotoxic than their nitrate analogues and an effect of the terpyridine ligand was also observed. The thermal stabilization profiles showed that the greatest stabilization of hybrid G4, Tel22, was observed for the Zn complexes bearing the terpyridine ligand that contained one or two methylated 4-(imidazol-1-yl)phenyl substituents, 3Cl and 3(L)2, respectively, probably due to their extra positive charge. Stability and aquation studies for these complexes were carried out and no ligand release was detected. Complexes 3Cl and 3(L)2 were successfully internalized by SW480 cells and they seemed to be localized mainly in the nucleolus. The highest cytotoxicity, G4 selectivity and G4 affinity determined by fluorescence and ITC experiments, and subcellular localization quantified by ICP-MS measurements, rendered 3Cl a very interesting complex from a biological standpoint.
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Affiliation(s)
- Natalia Busto
- Chemistry Department, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
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17
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Sanchez-Martin V, Soriano M, Garcia-Salcedo JA. Quadruplex Ligands in Cancer Therapy. Cancers (Basel) 2021; 13:3156. [PMID: 34202648 PMCID: PMC8267697 DOI: 10.3390/cancers13133156] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/18/2021] [Accepted: 06/20/2021] [Indexed: 02/07/2023] Open
Abstract
Nucleic acids can adopt alternative secondary conformations including four-stranded structures known as quadruplexes. To date, quadruplexes have been demonstrated to exist both in human chromatin DNA and RNA. In particular, quadruplexes are found in guanine-rich sequences constituting G-quadruplexes, and in cytosine-rich sequences forming i-Motifs as a counterpart. Quadruplexes are associated with key biological processes ranging from transcription and translation of several oncogenes and tumor suppressors to telomeres maintenance and genome instability. In this context, quadruplexes have prompted investigations on their possible role in cancer biology and the evaluation of small-molecule ligands as potential therapeutic agents. This review aims to provide an updated close-up view of the literature on quadruplex ligands in cancer therapy, by grouping together ligands for DNA and RNA G-quadruplexes and DNA i-Motifs.
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Affiliation(s)
- Victoria Sanchez-Martin
- Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain;
- Microbiology Unit, Biosanitary Research Institute IBS, University Hospital Virgen de las Nieves, 18014 Granada, Spain
- Department of Biochemistry, Molecular Biology III and Immunology, University of Granada, 18016 Granada, Spain
| | - Miguel Soriano
- Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain;
- Centre for Intensive Mediterranean Agrosystems and Agri-Food Biotechnology (CIAMBITAL), University of Almeria, 04001 Almeria, Spain
| | - Jose Antonio Garcia-Salcedo
- Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain;
- Microbiology Unit, Biosanitary Research Institute IBS, University Hospital Virgen de las Nieves, 18014 Granada, Spain
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18
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Platella C, Trajkovski M, Doria F, Freccero M, Plavec J, Montesarchio D. On the interaction of an anticancer trisubstituted naphthalene diimide with G-quadruplexes of different topologies: a structural insight. Nucleic Acids Res 2020; 48:12380-12393. [PMID: 33170272 PMCID: PMC7708068 DOI: 10.1093/nar/gkaa1001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/29/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Naphthalene diimides showed significant anticancer activity in animal models, with therapeutic potential related to their ability to strongly interact with G-quadruplexes. Recently, a trifunctionalized naphthalene diimide, named NDI-5, was identified as the best analogue of a mini-library of novel naphthalene diimides for its high G-quadruplex binding affinity along with marked, selective anticancer activity, emerging as promising candidate drug for in vivo studies. Here we used NMR, dynamic light scattering, circular dichroism and fluorescence analyses to investigate the interactions of NDI-5 with G-quadruplexes featuring either parallel or hybrid topology. Interplay of different binding modes of NDI-5 to G-quadruplexes was observed for both parallel and hybrid topologies, with end-stacking always operative as the predominant binding event. While NDI-5 primarily targets the 5'-end quartet of the hybrid G-quadruplex model (m-tel24), the binding to a parallel G-quadruplex model (M2) occurs seemingly simultaneously at the 5'- and 3'-end quartets. With parallel G-quadruplex M2, NDI-5 formed stable complexes with 1:3 DNA:ligand binding stoichiometry. Conversely, when interacting with hybrid G-quadruplex m-tel24, NDI-5 showed multiple binding poses on a single G-quadruplex unit and/or formed different complexes comprising two or more G-quadruplex units. NDI-5 produced stabilizing effects on both G-quadruplexes, forming complexes with dissociation constants in the nM range.
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Affiliation(s)
- Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, I-80126 Naples, Italy
| | - Marko Trajkovski
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Filippo Doria
- Department of Chemistry, University of Pavia, Viale Taramelli 10, I-27100 Pavia, Italy
| | - Mauro Freccero
- Department of Chemistry, University of Pavia, Viale Taramelli 10, I-27100 Pavia, Italy
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
- EN→FIST Centre of Excellence, Trg OF 13, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, I-80126 Naples, Italy
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19
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Vianney YM, Preckwinkel P, Mohr S, Weisz K. Quadruplex-Duplex Junction: A High-Affinity Binding Site for Indoloquinoline Ligands. Chemistry 2020; 26:16910-16922. [PMID: 32975874 PMCID: PMC7756412 DOI: 10.1002/chem.202003540] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/21/2020] [Indexed: 12/23/2022]
Abstract
A parallel quadruplex derived from the Myc promoter sequence was extended by a stem-loop duplex at either its 5'- or 3'-terminus to mimic a quadruplex-duplex (Q-D) junction as a potential genomic target. High-resolution structures of the hybrids demonstrate continuous stacking of the duplex on the quadruplex core without significant perturbations. An indoloquinoline ligand carrying an aminoalkyl side chain was shown to bind the Q-D hybrids with a very high affinity in the order Ka ≈107 m-1 irrespective of the duplex location at the quadruplex 3'- or 5'-end. NMR chemical shift perturbations identified the tetrad face of the Q-D junction as specific binding site for the ligand. However, calorimetric analyses revealed significant differences in the thermodynamic profiles upon binding to hybrids with either a duplex extension at the quadruplex 3'- or 5'-terminus. A large enthalpic gain and considerable hydrophobic effects are accompanied by the binding of one ligand to the 3'-Q-D junction, whereas non-hydrophobic entropic contributions favor binding with formation of a 2:1 ligand-quadruplex complex in case of the 5'-Q-D hybrid.
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Affiliation(s)
- Yoanes Maria Vianney
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Pit Preckwinkel
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Swantje Mohr
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
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20
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Schnarr L, Jana J, Preckwinkel P, Weisz K. Impact of a Snap-Back Loop on Stability and Ligand Binding to a Parallel G-Quadruplex. J Phys Chem B 2020; 124:2778-2787. [DOI: 10.1021/acs.jpcb.0c00700] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Lena Schnarr
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Strasse 4, D-17487 Greifswald, Germany
| | - Jagannath Jana
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Strasse 4, D-17487 Greifswald, Germany
| | - Pit Preckwinkel
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Strasse 4, D-17487 Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Strasse 4, D-17487 Greifswald, Germany
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21
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Funke A, Weisz K. Revealing the Energetics of Ligand-Quadruplex Interactions Using Isothermal Titration Calorimetry. Methods Mol Biol 2019; 2035:45-61. [PMID: 31444743 DOI: 10.1007/978-1-4939-9666-7_3] [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] [Indexed: 01/09/2023]
Abstract
The thermodynamic characterization of G4-ligand interactions has shown to be a powerful adjunct to structural information in the rational design and optimization of potent G-quadruplex ligands for use in therapeutics, diagnostics, or other technological applications. Isothermal titration calorimetry (ITC) can resolve energetic contributions to complex formation and constitutes the only available experimental method to directly measure binding enthalpies. A general protocol for using ITC in studies on quadruplex-ligand interactions with details on the experimental setup, data analysis, and potential pitfalls is presented. The methodologies used are illustrated on results obtained from the targeting of a parallel DNA G-quadruplex with a G4-binding indoloquinoline derivative.
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Affiliation(s)
- Andrea Funke
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany.
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22
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Funke A, Weisz K. Thermodynamic signature of indoloquinolines interacting with G-quadruplexes: Impact of ligand side chain. Biochimie 2018; 157:142-148. [PMID: 30481540 DOI: 10.1016/j.biochi.2018.11.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/22/2018] [Indexed: 10/27/2022]
Abstract
Binding of indoloquinolines with different aliphatic side chains to a parallel G-quadruplex derived from the MYC promoter sequence was characterized by optical and calorimetric measurements. ITC experiments performed at different temperatures enabled the determination of molar heat capacity changes upon quadruplex binding and a partitioning of the total binding free enthalpy into contributing terms with hydrophobic effects being major driving forces for all derivatives. Whereas affinities increase for indoloquinolines equipped with a long and positively charged side arm, the highest contribution of specific intermolecular interactions anticipated to impart enhanced specificity is found for a ligand with an uncharged ether aliphatic tail. Obtained thermodynamic signatures may considerably aid in the rational selection of ligand side chains for G-quadruplex binders with enhanced affinity or selectivity.
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Affiliation(s)
- Andrea Funke
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, D-17487, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff-Str. 4, D-17487, Greifswald, Germany.
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23
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Funke A, Karg B, Dickerhoff J, Balke D, Müller S, Weisz K. Ligand-Induced Dimerization of a Truncated Parallel MYC G-Quadruplex. Chembiochem 2018; 19:505-512. [PMID: 29228465 DOI: 10.1002/cbic.201700593] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Indexed: 02/04/2023]
Abstract
Binding of an indoloquinoline derivative with an aminoalkyl side chain to a truncated sequence from the MYC promoter region was studied through isothermal titration calorimetry (ITC). The targeted MYC3 sequence lacks 3'-flanking nucleotides and forms a monomeric parallel quadruplex (G4) with a blunt-ended 3'-outer tetrad under the solution conditions employed. Analysis of ITC isotherms reveals multiple binding equilibria with the initial formation of a 1:2 ligand/quadruplex complex. Evaluation of electrophoretic mobilities as well as NMR spectral data confirm ligand-induced dimerization of MYC3 quadruplexes with the ligand sandwiched between the two 3'-outer tetrads. Additional ligand molecules in excess bind to the 5'-outer tetrads of the sandwich complex. Such a ligand-promoted G4 dimerization may be exploited for the controlled assembly or disassembly of G4 aggregates to expand on present quadruplex-based technologies.
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Affiliation(s)
- Andrea Funke
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Beatrice Karg
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Jonathan Dickerhoff
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Darko Balke
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Sabine Müller
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
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24
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Deng N, Wickstrom L, Cieplak P, Lin C, Yang D. Resolving the Ligand-Binding Specificity in c-MYC G-Quadruplex DNA: Absolute Binding Free Energy Calculations and SPR Experiment. J Phys Chem B 2017; 121:10484-10497. [PMID: 29086571 DOI: 10.1021/acs.jpcb.7b09406] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We report the absolute binding free energy calculation and surface plasmon resonance (SPR) experiment for ligand binding with the c-MYC G-quadruplex DNA. The unimolecular parallel DNA G-quadruplex formed in nuclease hypersensitivity element III1 of the c-MYC gene promoter regulates the c-MYC transcription and is recognized as an emerging drug target for cancer therapy. Quindoline derivatives have been shown to stabilize the G-quadruplex and inhibit the c-MYC expression in cancer cells. NMR revealed two binding sites located at the 5' and 3' termini of the G-quadruplex. Questions about which site is more favored and the basis for the ligand-induced binding site formation remain unresolved. Here, we employ two absolute binding free energy methods, the double decoupling and the potential of mean force methods, to dissect the ligand-binding specificity in the c-MYC G-quadruplex. The calculated absolute binding free energies are in general agreement with the SPR result and suggest that quindoline has a slight preference for the 5' site. The flanking residues around the two sites undergo significant reorganization as the ligand unbinds, which provides evidence for ligand-induced binding pocket formation. The results help interpret experimental data and inform rational design of small molecules targeting the c-MYC G-quadruplex.
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Affiliation(s)
- Nanjie Deng
- Department of Chemistry and Physical Sciences, Pace University , 1 Pace Plaza, New York, New York 10038, United States
| | - Lauren Wickstrom
- Department of Science, Borough of Manhattan Community College, the City University of New York , New York, New York 10007, United States
| | - Piotr Cieplak
- Sanford Burnham Prebys Medical Discovery Institute , La Jolla, San Diego, California 92037, United States
| | - Clement Lin
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University , West Lafayette, Indiana 47907, United States
| | - Danzhou Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University , West Lafayette, Indiana 47907, United States
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25
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Nguyen TQN, Lim KW, Phan AT. A Dual-Specific Targeting Approach Based on the Simultaneous Recognition of Duplex and Quadruplex Motifs. Sci Rep 2017; 7:11969. [PMID: 28931822 PMCID: PMC5607247 DOI: 10.1038/s41598-017-10583-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/09/2017] [Indexed: 12/31/2022] Open
Abstract
Small-molecule ligands targeting nucleic acids have been explored as potential therapeutic agents. Duplex groove-binding ligands have been shown to recognize DNA in a sequence-specific manner. On the other hand, quadruplex-binding ligands exhibit high selectivity between quadruplex and duplex, but show limited discrimination between different quadruplex structures. Here we propose a dual-specific approach through the simultaneous application of duplex- and quadruplex-binders. We demonstrated that a quadruplex-specific ligand and a duplex-specific ligand can simultaneously interact at two separate binding sites of a quadruplex-duplex hybrid harbouring both quadruplex and duplex structural elements. Such a dual-specific targeting strategy would combine the sequence specificity of duplex-binders and the strong binding affinity of quadruplex-binders, potentially allowing the specific targeting of unique quadruplex structures. Future research can be directed towards the development of conjugated compounds targeting specific genomic quadruplex-duplex sites, for which the linker would be highly context-dependent in terms of length and flexibility, as well as the attachment points onto both ligands.
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Affiliation(s)
- Thi Quynh Ngoc Nguyen
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Kah Wai Lim
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Anh Tuân Phan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
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26
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Funke A, Weisz K. Comprehensive Thermodynamic Profiling for the Binding of a G-Quadruplex Selective Indoloquinoline. J Phys Chem B 2017; 121:5735-5743. [DOI: 10.1021/acs.jpcb.7b02686] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Andrea Funke
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
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28
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Mariz IFA, Pinto S, Lavrado J, Paulo A, Martinho JMG, Maçôas EMS. Cryptolepine and quindoline: understanding their photophysics. Phys Chem Chem Phys 2017; 19:10255-10263. [PMID: 28265616 DOI: 10.1039/c7cp00455a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Quindoline (QUIND, indolo[3,2-b]quinoline) and cryptolepine (CRYPT, 5-methyl-10H-indolo[3,2-b]quinoline) together with their corresponding derivatives have been studied for decades due to their important biological activity against diseases like malaria. The biological activity of drugs is routinely investigated using fluorescence based methods. However, recent reports show that the photophysics of CRYPT and its analogues is not yet understood. Herein, the photophysics of CRYPT and QUIND is studied in aqueous solutions at different pH values and in both protic and aprotic solvents of different polarities. CRYPT and QUIND are shown to exist in different prototropic forms depending on pH and solvent polarity. CRYPT is found to be more sensitive to the solvent nature. Both compounds are shown to have two-photon stimulated emission. Their two-photon absorption (TPA) cross-sections were measured in the 710-960 nm range. The TPA cross-section is relatively low but allows for the observation of both compounds in HEK 293 T cells, where CRYPT is found mostly in the nucleus and QUIND accumulates in the cytoplasm.
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Affiliation(s)
- Inês F A Mariz
- Centro de Química-Física Molecular (CQFM) and Institute of Nanoscience and Nanotechnology (IN), Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1,1049-001 Lisboa, Portugal.
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29
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Buchholz I, Karg B, Dickerhoff J, Sievers-Engler A, Lämmerhofer M, Weisz K. Selective Targeting of G-Quadruplex Structures by a Benzothiazole-Based Binding Motif. Chemistry 2017; 23:5814-5823. [PMID: 28276093 DOI: 10.1002/chem.201700298] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Indexed: 12/28/2022]
Abstract
A benzothiazole derivative was identified as potent ligand for DNA G-quadruplex structures. Fluorescence titrations revealed selective binding to quadruplexes of different topologies including parallel, antiparallel, and (3+1) hybrid structures. The parallel c-MYC sequence was found to constitute the preferred target with dissociation constants in the micromolar range. Binding of the benzothiazole-based ligand to c-MYC was structurally and thermodynamically characterized in detail by employing a comprehensive set of spectroscopic and calorimetric techniques. Job plot analyses and mass spectral data indicate noncooperative ligand binding to form complexes with 1:1 and 2:1 stoichiometries. Whereas stacking interactions are suggested by optical methods, NMR chemical shift perturbations also indicate significant rearrangements of both 5'- and 3'-flanking sequences upon ligand binding. Additional isothermal calorimetry studies yield a thermodynamic profile of the ligand-quadruplex association and reveal enthalpic contributions to be the major driving force for binding. Structural and thermodynamic information obtained in the present work provides the basis for the rational development of benzothiazole derivatives as promising quadruplex binding agents.
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Affiliation(s)
- Ina Buchholz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Beatrice Karg
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Jonathan Dickerhoff
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
| | - Adrian Sievers-Engler
- Institute of Pharmaceutical Sciences, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany
| | - Michael Lämmerhofer
- Institute of Pharmaceutical Sciences, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Strasse 4, 17487, Greifswald, Germany
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Wang X, Pei L, Fan X, Shi S. [Ru(L) 2 (3-tppp)] 2+ (L = bpy, phen) stabilizes two different forms of the human telomeric G-quadruplex DNA. INORG CHEM COMMUN 2016. [DOI: 10.1016/j.inoche.2016.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Ali A, Kamra M, Roy S, Muniyappa K, Bhattacharya S. Novel Oligopyrrole Carboxamide based Nickel(II) and Palladium(II) Salens, Their Targeting of Human G-Quadruplex DNA, and Selective Cancer Cell Toxicity. Chem Asian J 2016; 11:2542-54. [DOI: 10.1002/asia.201600655] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/16/2016] [Indexed: 01/22/2023]
Affiliation(s)
- Asfa Ali
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560 012 India
| | - Mohini Kamra
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560 012 India
| | - Soma Roy
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560 012 India
| | - K. Muniyappa
- Department of Biochemistry; Indian Institute of Science; Bangalore 560 012 India
| | - Santanu Bhattacharya
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560 012 India
- Director's Research Unit; Indian Association for the Cultivation of Science; Kolkata 700 032 India
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He L, Chen X, Meng Z, Wang J, Tian K, Li T, Shao F. Octahedral ruthenium complexes selectively stabilize G-quadruplexes. Chem Commun (Camb) 2016; 52:8095-8. [DOI: 10.1039/c6cc03117j] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Due to the unique three dimensional structures of Ru complexes, strong interactions such as H-bonds between the z-axial ligands and cation channels in G-quadruplexes enabled not only efficient stabilization of G-quadruplexes, but excellent binding resistance against duplex DNA.
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Affiliation(s)
- Lei He
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Xiang Chen
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Zhenyu Meng
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Jintao Wang
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Keyin Tian
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Tianhu Li
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Fangwei Shao
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
- Singapore
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