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Boissieras J, Granzhan A. Potentiometric titrations to study ligand interactions with DNA i-motifs. Methods Enzymol 2023; 695:233-254. [PMID: 38521587 DOI: 10.1016/bs.mie.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
i-Motifs are non-canonical secondary structures of DNA formed by mutual intercalation of hemi-protonated cytosine-cytosine base pairs, most typically in slightly acidic conditions (pH<7.0). These structures are well-studied in vitro and have recently been suggested to exist in cells. Despite nearly a decade of active research, the quest for small-molecule ligands that could selectively bind to and stabilize i-motifs continues, and no reference, bona fide i-motif ligand is currently available. This is, at least in part, due to the lack of robust methods to assess the interaction of ligands with i-motifs, since many techniques well-established for studies of other secondary structures (such as CD-, UV-, and FRET-melting) may generate artifacts when applied to i-motifs. Here, we describe an implementation of automated, potentiometric (pH) titrations as a robust isothermal method to assess the impact of ligands or cosolutes on thermodynamic stability of i-motifs. This approach is validated through the use of a cosolute previously known to stabilize i-motifs (PEG2000) and three small-molecule ligands that are able to stabilize, destabilize, or have no effect on the stability of i-motifs, respectively.
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Affiliation(s)
- Joseph Boissieras
- CMBC, CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Orsay, France; CMBC, CNRS UMR9187, INSERM U1196, Université Paris Saclay, Orsay, France
| | - Anton Granzhan
- CMBC, CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Orsay, France; CMBC, CNRS UMR9187, INSERM U1196, Université Paris Saclay, Orsay, France.
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2
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Das S, Takahashi S, Ohyama T, Bhowmik S, Sugimoto N. Theranostic approach to specifically targeting the interloop region of BCL2 i-motif DNA by crystal violet. Sci Rep 2023; 13:14338. [PMID: 37658102 PMCID: PMC10474294 DOI: 10.1038/s41598-023-39407-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/25/2023] [Indexed: 09/03/2023] Open
Abstract
Ligands that recognise specific i-motif DNAs are helpful in cancer diagnostics and therapeutics, as i-motif formation can cause cancer. Although the loop regions of i-motifs are promising targets for ligands, the interaction between a ligand and the loop regions based on sequence information remains unexplored. Herein, we investigated the loop regions of various i-motif DNAs to determine whether these regions specifically interact with fluorescent ligands. Crystal violet (CV), a triphenylmethane dye, exhibited strong fluorescence with the i-motif derived from the promoter region of the human BCL2 gene in a sequence- and structure-specific manner. Our systematic sequence analysis indicated that CV was bound to the site formed by the first and third loops through inter-loop interactions between the guanine bases present in these loops. As the structural stability of the BCL2 i-motif was unaffected by CV, the local stabilisation of the loops by CV could inhibit the interaction of transcription factors with these loops, repressing the BCL2 expression of MCF-7 cells. Our finding suggests that the loops of the i-motif can act as a novel platform for the specific binding of small molecules; thus, they could be utilised for the theranostics of diseases associated with i-motif DNAs.
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Affiliation(s)
- Sinjan Das
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan
| | - Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan
| | - Tatsuya Ohyama
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan
| | - Sudipta Bhowmik
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, A.P.C Road, Kolkata, 700009, India
- Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to be University), Pondy-Cuddalore Main Road, Pillayarkuppam, Pondicherry, 607402, India
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan.
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan.
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3
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Bag S, Ghosal S, Karmakar S, Pramanik G, Bhowmik S. Uncovering the Contrasting Binding Behavior of Plant Flavonoids Fisetin and Morin Having Subsidiary Hydroxyl Groups (-OH) with HRAS1 and HRAS2 i-Motif DNA Structures: Decoding the Structural Alterations and Positional Influences. ACS OMEGA 2023; 8:30315-30329. [PMID: 37636929 PMCID: PMC10448647 DOI: 10.1021/acsomega.3c03105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/18/2023] [Indexed: 08/29/2023]
Abstract
Research on the interactions of naturally existing flavonoids with various noncanonical DNA such as i-motif (IM) DNA structures is helpful in comprehending the molecular basis of binding mode as well as providing future direction for the application and invention of novel effective therapeutic drugs. IM DNA structures have been identified as prospective anticancer therapeutic targets, and flavonoids are smaller molecules with a variety of health-promoting attributes, including anticancer activities. The extensive investigation comprising a series of techniques reveals the contrasting mode of the binding behavior of fisetin and morin with various IM DNA structures. We have discovered that structural alterations of hydroxyl groups located at different places of aromatic rings influence flavonoid's reactivity. This minor structural alteration appears to be critical for fisetin and morin's capacity to interact differentially with HRAS1 and HRAS2 IM DNA. Hence, fisetin appears to be an efficient ligand for HRAS1 and morin is considered to be an efficient ligand for HRAS2 IM DNA. This novel exploration opens up the possibility of employing the strategy for regulation of gene expression in cancerous cells. Our finding also reveals the flavonoid-mediated specific interaction with IM DNA while pointing toward tangible strategies for drug discovery and other essential cellular functions.
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Affiliation(s)
- Sagar Bag
- Department
of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, A.P.C. Road, Kolkata 700009, India
| | - Souvik Ghosal
- Mahatma
Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth
(Deemed to be University), Pondy−Cuddalore Main Road, Pillaiyarkuppam, Pondicherry 607402, India
| | - Sudip Karmakar
- UGC−DAE
Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Bidhan Nagar, Kolkata 700 106, India
| | - Goutam Pramanik
- UGC−DAE
Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Bidhan Nagar, Kolkata 700 106, India
| | - Sudipta Bhowmik
- Department
of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, A.P.C. Road, Kolkata 700009, India
- Mahatma
Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth
(Deemed to be University), Pondy−Cuddalore Main Road, Pillaiyarkuppam, Pondicherry 607402, India
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4
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Luo X, Zhang J, Gao Y, Pan W, Yang Y, Li X, Chen L, Wang C, Wang Y. Emerging roles of i-motif in gene expression and disease treatment. Front Pharmacol 2023; 14:1136251. [PMID: 37021044 PMCID: PMC10067743 DOI: 10.3389/fphar.2023.1136251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 02/27/2023] [Indexed: 03/22/2023] Open
Abstract
As non-canonical nucleic acid secondary structures consisting of cytosine-rich nucleic acids, i-motifs can form under certain conditions. Several i-motif sequences have been identified in the human genome and play important roles in biological regulatory functions. Due to their physicochemical properties, these i-motif structures have attracted attention and are new targets for drug development. Herein, we reviewed the characteristics and mechanisms of i-motifs located in gene promoters (including c-myc, Bcl-2, VEGF, and telomeres), summarized various small molecule ligands that interact with them, and the possible binding modes between ligands and i-motifs, and described their effects on gene expression. Furthermore, we discussed diseases closely associated with i-motifs. Among these, cancer is closely associated with i-motifs since i-motifs can form in some regions of most oncogenes. Finally, we introduced recent advances in the applications of i-motifs in multiple areas.
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Affiliation(s)
| | | | | | | | | | | | | | - Chang Wang
- *Correspondence: Chang Wang, ; Yuqing Wang,
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5
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Berthiol F, Boissieras J, Bonnet H, Pierrot M, Philouze C, Poisson JF, Granzhan A, Dejeu J, Defrancq E. Novel Synthesis of IMC-48 and Affinity Evaluation with Different i-Motif DNA Sequences. Molecules 2023; 28:molecules28020682. [PMID: 36677740 PMCID: PMC9865601 DOI: 10.3390/molecules28020682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
During the last decade, the evidence for the biological relevance of i-motif DNA (i-DNA) has been accumulated. However, relatively few molecules were reported to interact with i-DNA, and a controversy concerning their binding mode, affinity, and selectivity persists in the literature. In this context, the cholestane derivative IMC-48 has been reported to modulate bcl-2 gene expression by stabilizing an i-motif structure in its promoter. In the present contribution, we report on a novel, more straightforward, synthesis of IMC-48 requiring fewer steps compared to the previous approach. Furthermore, the interaction of IMC-48 with four different i-motif DNA sequences was thoroughly investigated by bio-layer interferometry (BLI) and circular dichroism (CD) spectroscopy. Surprisingly, our results show that IMC-48 is a very weak ligand of i-DNA as no quantifiable interaction or significant stabilization of i-motif structures could be observed, stimulating a quest for an alternative mechanism of its biological activity.
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Affiliation(s)
- Florian Berthiol
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
- Correspondence: (F.B.); (J.D.); (E.D.)
| | - Joseph Boissieras
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France
- CNRS UMR9187, INSERM U1196, Université Paris Saclay, F-91405 Orsay, France
| | - Hugues Bonnet
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Marie Pierrot
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Christian Philouze
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Jean-François Poisson
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Anton Granzhan
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France
- CNRS UMR9187, INSERM U1196, Université Paris Saclay, F-91405 Orsay, France
| | - Jérôme Dejeu
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, F-25000 Besançon, France
- Correspondence: (F.B.); (J.D.); (E.D.)
| | - Eric Defrancq
- Department of Molecular Chemistry (DCM), CNRS, UMR 5250, Université Grenoble-Alpes, 38000 Grenoble, France
- Correspondence: (F.B.); (J.D.); (E.D.)
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6
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Bonnet H, Morel M, Devaux A, Boissieras J, Granzhan A, Elias B, Lavergne T, Dejeu J, Defrancq E. Assessment of presumed small-molecule ligands of telomeric i-DNA by biolayer interferometry (BLI). Chem Commun (Camb) 2022; 58:5116-5119. [PMID: 35380138 DOI: 10.1039/d2cc00836j] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biolayer interferometry (BLI) and circular dichroism (CD) spectroscopy were used to investigate the interaction between previously reported i-motif DNA (i-DNA) ligands and folded or unfolded i-DNA in acidic (pH 5.5) and near-neutral (pH 6.5) conditions. We observed that although several ligands, in particular macrocyclic bis-acridine (BisA) and pyridostatin (PDS), showed good affinities for the telomeric i-motif forming sequence, none of the ligands displayed selective interactions with the i-DNA structure nor was able to promote its formation.
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Affiliation(s)
- Hugues Bonnet
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France.
| | - Maéva Morel
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France.
| | - Alexandre Devaux
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France.
| | - Joseph Boissieras
- Institut Curie, CNRS UMR 9187, INSERM U1196, Université Paris Saclay, 91405 Orsay, France
| | - Anton Granzhan
- Institut Curie, CNRS UMR 9187, INSERM U1196, Université Paris Saclay, 91405 Orsay, France
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Place Louis Pasteur 1, 1348 Louvain-la-Neuve, Belgium
| | - Thomas Lavergne
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France.
| | - Jérôme Dejeu
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France. .,FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, F-25000 Besançon, France
| | - Eric Defrancq
- Université Grenoble Alpes, Département de Chimie Moléculaire, UMR CNRS 5250, CS 40700-38058 Grenoble, France.
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7
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Stability and context of intercalated motifs (i-motifs) for biological applications. Biochimie 2022; 198:33-47. [PMID: 35259471 DOI: 10.1016/j.biochi.2022.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/21/2022] [Accepted: 03/03/2022] [Indexed: 11/24/2022]
Abstract
DNA is naturally dynamic and can self-assemble into alternative secondary structures including the intercalated motif (i-motif), a four-stranded structure formed in cytosine-rich DNA sequences. Until recently, i-motifs were thought to be unstable in physiological cellular environments. Studies demonstrating their existence in the human genome and role in gene regulation are now shining light on their biological relevance. Herein, we review the effects of epigenetic modifications on i-motif structure and stability, and biological factors that affect i-motif formation within cells. Furthermore, we highlight recent progress in targeting i-motifs with structure-specific ligands for biotechnology and therapeutic purposes.
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8
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Itaya R, Idei W, Nakamura T, Nishihara T, Kurihara R, Okamoto A, Tanabe K. Changes of C≡C Triple Bond Vibration that Disclosed Non-Canonical Cytosine Protonation in i-Motif-Forming Oligodeoxynucleotides. ACS OMEGA 2021; 6:31595-31604. [PMID: 34869984 PMCID: PMC8637604 DOI: 10.1021/acsomega.1c04074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/05/2021] [Indexed: 05/09/2023]
Abstract
Non-canonical protonation at cytosine (C) in DNA is related to a formation of second order DNA structures such as i-motif, which has a role in gene regulation. Although the detailed structural information is indispensable for comprehension of their functions in cells, the protonation status of C in complicated environments is still elusive. To provide a reporter system of non-canonical protonation, we focused on the molecular vibration that could be monitored using the Raman spectroscopy. We prepared a cytosine derivative (PC) with an acetylene unit as a Raman tag, and found that the Raman signal of acetylene in PC in oligodeoxynucleotides (ODNs) changed due to protonation at the cytosine ring which shortened an acetylene bond. The signal change in i-motif-forming ODNs was also observed in crowded environments with polyethylene glycol, evidencing protonation in i-motif DNA in complicated environments. This system would be one of tracking tools for protonation in DNA structures.
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Affiliation(s)
- Ryota Itaya
- Department
of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Wakana Idei
- Department
of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Takashi Nakamura
- Faculty
of Bioscience, Nagahama Institute of Bio-Science
and Technology, 1266
Tamura-cho, Nagahama 526-0829, Japan
| | - Tatsuya Nishihara
- Department
of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Ryohsuke Kurihara
- School
of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Akimitsu Okamoto
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Kazuhito Tanabe
- Department
of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
- . Phone: +81-42-759-6229. Fax: +81-42-759-6493
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Zhu Y, Li Z, Wang P, Qiu QM, Ma H, Li H. The Research of G-Motif Construction and Chirality in Deoxyguanosine Monophosphate Nucleotide Complexes. Front Chem 2021; 9:709777. [PMID: 34277575 PMCID: PMC8278404 DOI: 10.3389/fchem.2021.709777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
A detailed understanding of the mismatched base-pairing interactions in DNA will help reveal genetic diseases and provide a theoretical basis for the development of targeted drugs. Here, we utilized mononucleotide fragment to simulate mismatch DNA interactions in a local hydrophobic microenvironment. The bipyridyl-type bridging ligands were employed as a mild stabilizer to stabilize the GG mismatch containing complexes, allowing mismatch to be visualized based on X-ray crystallography. Five single crystals of 2′-deoxyguanosine–5′–monophosphate (dGMP) metal complexes were designed and obtained via the process of self-assembly. Crystallographic studies clearly reveal the details of the supramolecular interaction between mononucleotides and guest intercalators. A novel guanine–guanine base mismatch pattern with unusual (high anti)–(high anti) type of arrangement around the glycosidic angle conformations was successfully constructed. The solution state 1H–NMR, ESI–MS spectrum studies, and UV titration experiments emphasize the robustness of this g–motif in solution. Additionally, we combined the methods of single-crystal and solution-, solid-state CD spectrum together to discuss the chirality of the complexes. The complexes containing the g–motif structure, which reduces the energy of the system, following the solid-state CD signals, generally move in the long-wave direction. These results provided a new mismatched base pairing, that is g–motif. The interaction mode and full characterizations of g–motif will contribute to the study of the mismatched DNA interaction.
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Affiliation(s)
- Yanhong Zhu
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Zhongkui Li
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Pengfei Wang
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Qi-Ming Qiu
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Hongwei Ma
- Analytical and Testing Centre, Beijing Institute of Technology, Beijing, China
| | - Hui Li
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
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MD-TSPC4: Computational Method for Predicting the Thermal Stability of I-Motif. Int J Mol Sci 2020; 22:ijms22010061. [PMID: 33374624 PMCID: PMC7793491 DOI: 10.3390/ijms22010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 11/23/2022] Open
Abstract
I-Motif is a tetrameric cytosine-rich DNA structure with hemi-protonated cytosine: cytosine base pairs. Recent evidence showed that i-motif structures in human cells play regulatory roles in the genome. Therefore, characterization of novel i-motifs and investigation of their functional implication are urgently needed for comprehensive understanding of their roles in gene regulation. However, considering the complications of experimental investigation of i-motifs and the large number of putative i-motifs in the genome, development of an in silico tool for the characterization of i-motifs in the high throughput scale is necessary. We developed a novel computation method, MD-TSPC4, to predict the thermal stability of i-motifs based on molecular modeling and molecular dynamic simulation. By assuming that the flexibility of loops in i-motifs correlated with thermal stability within certain temperature ranges, we evaluated the correlation between the root mean square deviations (RMSDs) of model structures and the thermal stability as the experimentally obtained melting temperature (Tm). Based on this correlation, we propose an equation for Tm prediction from RMSD. We expect this method can be useful for estimating the overall structure and stability of putative i-motifs in the genome, which can be a starting point of further structural and functional studies of i-motifs.
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11
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Baptista FR, Devereux SJ, Gurung SP, Hall JP, Sazanovich IV, Towrie M, Cardin CJ, Brazier JA, Kelly JM, Quinn SJ. The influence of loops on the binding of the [Ru(phen) 2dppz] 2+ light-switch compound to i-motif DNA structures revealed by time-resolved spectroscopy. Chem Commun (Camb) 2020; 56:9703-9706. [PMID: 32699864 DOI: 10.1039/d0cc03702h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ultrafast time resolved infrared (TRIR) is used to report on the binding site of the "light-switch" complex [Ru(phen)2(dppz)]2+1 to i-motif structures in solution. Detailed information is provided due to perturbation of the local base vibrations by a 'Stark-like' effect which is used to establish the contribution of thymine base loop interactions to the binding site of 1 in this increasingly relevant DNA structure.
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12
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Spence P, Fielden J, Waller ZAE. Beyond Solvent Exclusion: i-Motif Detecting Capability and an Alternative DNA Light-Switching Mechanism in a Ruthenium(II) Polypyridyl Complex. J Am Chem Soc 2020; 142:13856-13866. [DOI: 10.1021/jacs.0c04789] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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