1
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Piantanida L, Dickinson GD, Majikes JM, Clay W, Liddle JA, Andersen T, Hayden EJ, Kuang W, Hughes WL. DNA-PAINT Probe Modifications Support High-Resolution Imaging with Shorter Binding Domains. ACS NANO 2024; 18:22369-22377. [PMID: 39109416 DOI: 10.1021/acsnano.4c06886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
DNA-based Points Accumulation for Imaging in Nanoscale Topography (DNA-PAINT) is an effective super resolution microscopy technique, and its optimization is key to improve nanoscale detection. The state-of-the-art improvements that are at the base of this optimization have been first routinely validated on DNA nanostructure devices before being tested on biological samples. This allows researchers to finely tune DNA-PAINT imaging features in a more controllable in vitro environment. Dye-labeled oligonucleotide probes with short hybridization domains can expand DNA-PAINT's detection by targeting short nucleotide sequences and improving resolution, speed, and multiplexing. However, developing these probes is challenging as their brief bound state makes them difficult to capture under routine imaging conditions. To extend dwell binding times and promote duplex stability, we introduced structural and chemical modifications to our imager probes. The modifications included mini-hairpins and/or Bridged Nucleic Acids (BNA); both of which increase the thermomechanical stability of a DNA duplex. Using this approach we demonstrate DNA-PAINT imaging with approximately 5 nm resolution using a 4-nucleotide hybridization domain that is 43% shorter than previously reported probes. Imager probes with such short hybridization domains are key for improving detection on DNA nanostructure devices because they have the capability to target a larger number of binding domains per localization unit. This is essential for metrology applications such as Nucleic Acid Memory (NAM) where the information density is dependent on the binding site length. The selected imager probes reported here present imaging resolution equivalent to current state-of-the-art DNA-PAINT probes, creating a strategy to image shorter DNA domains for nanoscience and nanotechnology alike.
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Affiliation(s)
- Luca Piantanida
- Micron School of Materials Science & Engineering, Boise State University, Boise, Idaho 83725, United States
| | - George D Dickinson
- Micron School of Materials Science & Engineering, Boise State University, Boise, Idaho 83725, United States
| | - Jacob M Majikes
- National Institute of Standards and Technology, Gaithersburg, Maryland 20878, United States
| | - William Clay
- Micron School of Materials Science & Engineering, Boise State University, Boise, Idaho 83725, United States
| | - J Alexander Liddle
- National Institute of Standards and Technology, Gaithersburg, Maryland 20878, United States
| | - Tim Andersen
- Department of Computer Science, Boise State University, Boise, Idaho 83725, United States
| | - Eric J Hayden
- Micron School of Materials Science & Engineering, Boise State University, Boise, Idaho 83725, United States
- Department of Biological Sciences, Boise State University, Boise, Idaho 83725, United States
| | - Wan Kuang
- Department of Electrical & Computer Engineering, Boise State University, Boise, Idaho 83725, United States
| | - William L Hughes
- Micron School of Materials Science & Engineering, Boise State University, Boise, Idaho 83725, United States
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2
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Sun W, Hu K, Liu M, Luo J, An R, Liang X. Facile Splint-Free Circularization of ssDNA with T4 DNA Ligase by Redesigning the Linear Substrate to Form an Intramolecular Dynamic Nick. Biomolecules 2024; 14:1027. [PMID: 39199414 PMCID: PMC11352879 DOI: 10.3390/biom14081027] [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: 07/30/2024] [Revised: 08/11/2024] [Accepted: 08/15/2024] [Indexed: 09/01/2024] Open
Abstract
The efficient preparation of single-stranded DNA (ssDNA) rings, as a macromolecular construction approach with topological features, has aroused much interest due to the ssDNA rings' numerous applications in biotechnology and DNA nanotechnology. However, an extra splint is essential for enzymatic circularization, and by-products of multimers are usually present at high concentrations. Here, we proposed a simple and robust strategy using permuted precursor (linear ssDNA) for circularization by forming an intramolecular dynamic nick using a part of the linear ssDNA substrate itself as the template. After the simulation of the secondary structure for desired circular ssDNA, the linear ssDNA substrate is designed to have its ends on the duplex part (≥5 bp). By using this permuted substrate with 5'-phosphate, the splint-free circularization is simply carried out by T4 DNA ligase. Very interestingly, formation of only several base pairs (2-4) flanking the nick is enough for ligation, although they form only instantaneously under ligation conditions. More significantly, the 5-bp intramolecular duplex part commonly exists in genomes or functional DNA, demonstrating the high generality of our approach. Our findings are also helpful for understanding the mechanism of enzymatic DNA ligation from the viewpoint of substrate binding.
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Affiliation(s)
- Wenhua Sun
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
| | - Kunling Hu
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
| | - Mengqin Liu
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
| | - Jian Luo
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
| | - Ran An
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, No. 1 Wenhai Road, Qingdao 266237, China
| | - Xingguo Liang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No. 1299 Sansha Road, Qingdao 266404, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Center, No. 1 Wenhai Road, Qingdao 266237, China
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3
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Carvajal-Maldonado D, Li Y, Returan M, Averill AM, Doublié S, Wood RD. Dynamic stem-loop extension by Pol θ and templated insertion during DNA repair. J Biol Chem 2024; 300:107461. [PMID: 38876299 PMCID: PMC11292364 DOI: 10.1016/j.jbc.2024.107461] [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: 04/17/2024] [Revised: 05/26/2024] [Accepted: 05/28/2024] [Indexed: 06/16/2024] Open
Abstract
Theta-mediated end joining (TMEJ) is critical for survival of cancer cells when other DNA double-stranded break repair pathways are impaired. Human DNA polymerase theta (Pol θ) can extend ssDNA oligonucleotides, but little is known about preferred substrates and mechanism. We show that Pol θ can extend both ssDNA and RNA substrates by unimolecular stem-loop synthesis initiated by only two 3' terminal base pairs. Given sufficient time, Pol θ uses alternative pairing configurations that greatly expand the repertoire of sequence outcomes. Further primer-template adjustments yield low-fidelity outcomes when the nucleotide pool is imbalanced. Unimolecular stem-loop synthesis competes with bimolecular end joining, even when a longer terminal microhomology for end joining is available. Both reactions are partially suppressed by the ssDNA-binding protein replication protein A. Protein-primer grasp residues that are specific to Pol θ are needed for rapid stem-loop synthesis. The ability to perform stem-loop synthesis from a minimally paired primer is rare among human DNA polymerases, but we show that human DNA polymerases Pol η and Pol λ can catalyze related reactions. Using purified human Pol θ, we reconstituted in vitro TMEJ incorporating an insertion arising from a stem-loop extension. These activities may help explain TMEJ repair events that include inverted repeat sequences.
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Affiliation(s)
- Denisse Carvajal-Maldonado
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - Yuzhen Li
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - Mark Returan
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - April M Averill
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA.
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4
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Wieruszewska J, Pawłowicz A, Połomska E, Pasternak K, Gdaniec Z, Andrałojć W. The 8-17 DNAzyme can operate in a single active structure regardless of metal ion cofactor. Nat Commun 2024; 15:4218. [PMID: 38760331 PMCID: PMC11101458 DOI: 10.1038/s41467-024-48638-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 05/09/2024] [Indexed: 05/19/2024] Open
Abstract
DNAzymes - synthetic enzymes made of DNA - have long attracted attention as RNA-targeting therapeutic agents. Yet, as of now, no DNAzyme-based drug has been approved, partially due to our lacking understanding of their molecular mode of action. In this work we report the solution structure of 8-17 DNAzyme bound to a Zn2+ ion solved through NMR spectroscopy. Surprisingly, it turned out to be very similar to the previously solved Pb2+-bound form (catalytic domain RMSD = 1.28 Å), despite a long-standing literature consensus that Pb2+ recruits a different DNAzyme fold than other metal ion cofactors. Our follow-up NMR investigations in the presence of other ions - Mg2+, Na+, and Pb2+ - suggest that at DNAzyme concentrations used in NMR all these ions induce a similar tertiary fold. Based on these findings, we propose a model for 8-17 DNAzyme interactions with metal ions postulating the existence of only a single catalytically-active structure, yet populated to a different extent depending on the metal ion cofactor. Our results provide structural information on the 8-17 DNAzyme in presence of non-Pb2+ cofactors, including the biologically relevant Mg2+ ion.
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Affiliation(s)
- Julia Wieruszewska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland
| | - Aleksandra Pawłowicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland
| | - Ewa Połomska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland
| | - Karol Pasternak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland
| | - Zofia Gdaniec
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland
| | - Witold Andrałojć
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704, Poznań, Noskowskiego, 12/14, Poland.
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5
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Carvajal-Maldonado D, Zahn K, Jensen R, Wood RD, Doublié S. Human DNA polymerase θ does not harbor intrinsic nuclease activity. Mol Cell 2024; 84:1394-1395. [PMID: 38640889 DOI: 10.1016/j.molcel.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 04/21/2024]
Affiliation(s)
- Denisse Carvajal-Maldonado
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, TX, USA
| | - Karl Zahn
- Repare Therapeutics, 7210 rue Frederick-Banting bureau 100, Saint-Laurent, QC H4S 2A1, Canada
| | - Ryan Jensen
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, TX, USA.
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA.
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6
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Wan J, Nytka M, Qian H, Lemr K, Tureček F. Do d(GCGAAGC) Cations Retain the Hairpin Structure in the Gas Phase? A Cyclic Ion Mobility Mass Spectrometry and Density Functional Theory Computational Study. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2323-2340. [PMID: 37696624 DOI: 10.1021/jasms.3c00228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
d(GCGAAGC) is the smallest oligonucleotide with a well-defined hairpin structure in solution. We report a study of multiply protonated d(GCGAAGC) and its sequence-scrambled isomers, d(CGAAGCG), d(GCGAACG), and d(CGGAAGC), that were produced by electrospray ionization with the goal of investigating their gas-phase structures and dissociations. Cyclic ion mobility measurements revealed that dications of d(GCGAAGC) as well as the scrambled-sequence ions were mixtures of protomers and/or conformers that had collision cross sections (CCS) within a 439-481 Å2 range. Multiple ion conformers were obtained by electrospray under native conditions as well as from aqueous methanol. Arrival time distribution profiles were characteristic of individual isomeric heptanucleotides. Extensive Born-Oppenheimer molecular dynamics (BOMD) and density functional theory (DFT) calculations of d(GCGAAGC)2+ isomers indicated that hairpin structures were high-energy isomers of more compact distorted conformers. Protonation caused a break up of the C2···G6 pair that was associated with the formation of strong hydrogen bonds in zwitterionic phosphate anion-nucleobase cation motifs that predominated in low energy ions. Multiple components were also obtained for d(GCGAAGC)3+ trications under native and denaturing electrospray conditions. The calculated trication structures showed disruption of the G···C pairs in low energy zwitterions. A hairpin trication was calculated to be a high energy isomer. d(GCGAAGC)4+ tetracations were produced and separated by c-IMS as two major isomers. All low energy d(GCGAAGC)4+ ions obtained by DFT geometry optimizations were zwitterions in which all five purine bases were protonated, and the ion charge was balanced by a phosphate anion. Tetracations of the scrambled sequences were each formed as one dominant isomer. The CCS calculated with the MobCal-MPI method were found to closely match experimental values. Collision-induced dissociation (CID) spectra of multiply charged heptanucleotides showed nucleobase loss and backbone cleavages occurring chiefly at the terminal nucleosides. Electron-transfer-CID tandem mass spectra were used to investigate dissociations of different charge and spin states of charge-reduced heptanucleotide cation radicals.
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Affiliation(s)
- Jiahao Wan
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Marianna Nytka
- Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 779 00 Olomouc, Czech Republic
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Haocheng Qian
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Karel Lemr
- Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 779 00 Olomouc, Czech Republic
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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7
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Andrałojć W, Wieruszewska J, Pasternak K, Gdaniec Z. Solution Structure of a Lanthanide-binding DNA Aptamer Determined Using High Quality pseudocontact shift restraints. Chemistry 2022; 28:e202202114. [PMID: 36043489 PMCID: PMC9828363 DOI: 10.1002/chem.202202114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Indexed: 01/12/2023]
Abstract
In this contribution we report the high-resolution NMR structure of a recently identified lanthanide-binding aptamer (LnA). We demonstrate that the rigid lanthanide binding by LnA allows for the measurement of anisotropic paramagnetic NMR restraints which to date remain largely inaccessible for nucleic acids. One type of such restraints - pseudocontact shifts (PCS) induced by four different paramagnetic lanthanides - was extensively used throughout the current structure determination study and the measured PCS turned out to be exceptionally well reproduced by the final aptamer structure. This finding opens the perspective for a broader application of paramagnetic effects in NMR studies of nucleic acids through the transplantation of the binding site found in LnA into other DNA/RNA systems.
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Affiliation(s)
- Witold Andrałojć
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Julia Wieruszewska
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Karol Pasternak
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Zofia Gdaniec
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
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8
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Kaczmarczyk AP, Déclais AC, Newton MD, Boulton SJ, Lilley DMJ, Rueda DS. Search and processing of Holliday junctions within long DNA by junction-resolving enzymes. Nat Commun 2022; 13:5921. [PMID: 36207294 PMCID: PMC9547003 DOI: 10.1038/s41467-022-33503-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/21/2022] [Indexed: 12/05/2022] Open
Abstract
Resolution of Holliday junctions is a critical intermediate step of homologous recombination in which junctions are processed by junction-resolving endonucleases. Although binding and cleavage are well understood, the question remains how the enzymes locate their substrate within long duplex DNA. Here we track fluorescent dimers of endonuclease I on DNA, presenting the complete single-molecule reaction trajectory for a junction-resolving enzyme finding and cleaving a Holliday junction. We show that the enzyme binds remotely to dsDNA and then undergoes 1D diffusion. Upon encountering a four-way junction, a catalytically-impaired mutant remains bound at that point. An active enzyme, however, cleaves the junction after a few seconds. Quantitative analysis provides a comprehensive description of the facilitated diffusion mechanism. We show that the eukaryotic junction-resolving enzyme GEN1 also undergoes facilitated diffusion on dsDNA until it becomes located at a junction, so that the general resolution trajectory is probably applicable to many junction resolving enzymes.
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Affiliation(s)
- Artur P Kaczmarczyk
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, W12 0NN, UK
| | | | - Matthew D Newton
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, W12 0NN, UK
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Simon J Boulton
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - David M J Lilley
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
| | - David S Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, W12 0NN, UK.
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, W12 0NN, UK.
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9
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Luo J, Chen H, An R, Liang X. Efficient preparation of AppDNA/AppRNA by T4 DNA ligase aided by a DNA involving mismatched mini-hairpin structure at its 3′ side. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20220199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jian Luo
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
| | - Hui Chen
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
| | - Ran An
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, P. R. China
| | - Xingguo Liang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, P. R. China
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10
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Song M, Li Y, Gao R, Liu J, Huang Q. De novo design of DNA aptamers that target okadaic acid (OA) by docking-then-assembling of single nucleotides. Biosens Bioelectron 2022; 215:114562. [PMID: 35870338 DOI: 10.1016/j.bios.2022.114562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 06/24/2022] [Accepted: 07/07/2022] [Indexed: 11/15/2022]
Abstract
Okadaic acid (OA) is a diarrhetic shellfish poison widespread in ocean, so its detection is of great significance to seafood safety. Because of good sensitivity and low cost, biosensors using nucleic-acid aptamers as the recognition molecules are emerging as an important detection tool. However, the traditional SELEX screening method for acquiring OA high-affinity aptamers is time- and resource-intensive. Alternatively, here we developed a de novo design method based on the 3D structure of a target molecule, such as OA. Without experimental screening, this method designs OA aptamers by a computational approach of docking-then-assembling (DTA) of single nucleotides (A, C, G and T) as: (1) determining the high-affinity nucleotide binding sites of the target molecule via saturated molecular docking; (2) assembling the bound nucleotides into binding units to the target molecule; (3) constructing full-length aptamers by introducing stabilizing units to connect these binding units. In this way, five OA aptamers were designed, and microscale thermophoresis (MST) experiments verified that their Kd values are in the range of 100-600 nM; and one of them (named 9CGAT_4_a) could specifically bind to OA with low affinities for the other three marine biotoxins. Therefore, this study provides high-affinity and specific aptamers for the development of OA biosensors, and presents a promising de novo design method applicable to other target molecules.
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Affiliation(s)
- Menghua Song
- State Key Laboratory of Genetic Engineering, Shanghai Engineering Research Center of Industrial Microorganisms, MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yuanyuan Li
- State Key Laboratory of Genetic Engineering, Shanghai Engineering Research Center of Industrial Microorganisms, MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Ruihua Gao
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Jianping Liu
- State Key Laboratory of Genetic Engineering, Shanghai Engineering Research Center of Industrial Microorganisms, MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Qiang Huang
- State Key Laboratory of Genetic Engineering, Shanghai Engineering Research Center of Industrial Microorganisms, MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China; Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, 201203, China.
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11
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Competitive ELISA for a serologic test to detect dengue serotype-specific anti-NS1 IgGs using high-affinity UB-DNA aptamers. Sci Rep 2021; 11:18000. [PMID: 34504185 PMCID: PMC8429655 DOI: 10.1038/s41598-021-97339-8] [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: 04/16/2021] [Accepted: 08/24/2021] [Indexed: 02/08/2023] Open
Abstract
Serologic tests to detect specific IgGs to antigens related to viral infections are urgently needed for diagnostics and therapeutics. We present a diagnostic method for serotype-specific IgG identification of dengue infection by a competitive enzyme-linked immunosorbent assay (ELISA), using high-affinity unnatural-base-containing DNA (UB-DNA) aptamers that recognize the four categorized serotypes. Using UB-DNA aptamers specific to each serotype of dengue NS1 proteins (DEN-NS1), we developed our aptamer-antibody sandwich ELISA for dengue diagnostics. Furthermore, IgGs highly specific to DEN-NS1 inhibited the serotype-specific NS1 detection, inspiring us to develop the competitive ELISA format for dengue serotype-specific IgG detection. Blood samples from Singaporean patients with primary or secondary dengue infections confirmed the highly specific IgG detection of this format, and the IgG production initially reflected the serotype of the past infection, rather than the recent infection. Using this dengue competitive ELISA format, cross-reactivity tests of 21 plasma samples from Singaporean Zika virus-infected patients revealed two distinct patterns: 8 lacked cross-reactivity, and 13 were positive with unique dengue serotype specificities, indicating previous dengue infection. This antigen-detection ELISA and antibody-detection competitive ELISA combination using the UB-DNA aptamers identifies both past and current viral infections and will facilitate specific medical care and vaccine development for infectious diseases.
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12
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McAdorey A, Bennett HA, Vanloon J, Yan H. Use of anion-exchange HPLC to study DNA conformational polymorphism. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1180:122890. [PMID: 34403914 DOI: 10.1016/j.jchromb.2021.122890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 07/30/2021] [Indexed: 10/20/2022]
Abstract
Anion-exchange chromatography carried out under non-denaturing conditions is a versatile tool to differentiate DNA conformations. In this work, the utility of this form of HPLC was demonstrated in four examples. The hairpin and duplex forms of d(CG)9 were readily resolved, which allowed for the studies of the influence of salt on the equilibrium of these two forms of secondary structures. Similarly, the minimum size of Tn in the loop region required for the sequence 5'-d(CCCAA-(T)n-TTGGG)-3' to form hairpin was established to be two nucleotides using anion-exchange HPLC and fluorescence resonance energy transfer. Furthermore, the efficiency of hybridization of partially self-complementary sequences d[(CG)6Nx] was readily monitored by non-denaturing anion-exchange HPLC. Finally, different structures adopted by quadruplex-forming sequences were resolved in the same manner.
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Affiliation(s)
- Alyssa McAdorey
- Department of Chemistry and Centre for Biotechnology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Hayley-Ann Bennett
- Department of Chemistry and Centre for Biotechnology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Jesse Vanloon
- Department of Chemistry and Centre for Biotechnology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Hongbin Yan
- Department of Chemistry and Centre for Biotechnology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada.
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13
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Matsunaga KI, Kimoto M, Lim VW, Tan HP, Wong YQ, Sun W, Vasoo S, Leo YS, Hirao I. High-affinity five/six-letter DNA aptamers with superior specificity enabling the detection of dengue NS1 protein variants beyond the serotype identification. Nucleic Acids Res 2021; 49:11407-11424. [PMID: 34169309 PMCID: PMC8599795 DOI: 10.1093/nar/gkab515] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/24/2021] [Accepted: 06/04/2021] [Indexed: 12/25/2022] Open
Abstract
Genetic alphabet expansion of DNA by introducing unnatural bases (UBs), as a fifth letter, dramatically augments the affinities of DNA aptamers that bind to target proteins. To determine whether UB-containing DNA (UB-DNA) aptamers obtained by affinity selection could spontaneously achieve high specificity, we have generated a series of UB-DNA aptamers (KD: 27-182 pM) targeting each of four dengue non-structural protein 1 (DEN-NS1) serotypes. The specificity of each aptamer is remarkably high, and the aptamers can recognize the subtle variants of DEN-NS1 with at least 96.9% amino acid sequence identity, beyond the capability of serotype identification (69-80% sequence identities). Our UB-DNA aptamers specifically identified two major variants of dengue serotype 1 with 10-amino acid differences in the DEN-NS1 protein (352 aa) in Singaporeans' clinical samples. These results suggest that the high-affinity UB-DNA aptamers generated by affinity selection also acquire high target specificity. Intriguingly, one of the aptamers contained two different UBs as fifth and sixth letters, which are essential for the tight binding to the target. These two types of unnatural bases with distinct physicochemical properties profoundly expand the potential of DNA aptamers. Detection methods incorporating the UB-DNA aptamers will facilitate precise diagnoses of viral infections and other diseases.
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Affiliation(s)
- Ken-Ichiro Matsunaga
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
| | - Michiko Kimoto
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
| | - Vanessa Weixun Lim
- National Centre for Infectious Diseases, 16 Jalan Tan Tock Seng, Singapore 308442, Singapore
| | - Hui Pen Tan
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
| | - Yu Qian Wong
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
| | - William Sun
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
| | - Shawn Vasoo
- National Centre for Infectious Diseases, 16 Jalan Tan Tock Seng, Singapore 308442, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Dr., Experimental Medicine Building, Singapore 636921, Singapore
| | - Yee Sin Leo
- National Centre for Infectious Diseases, 16 Jalan Tan Tock Seng, Singapore 308442, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Dr., Experimental Medicine Building, Singapore 636921, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, 12 Science Drive 2, #10-01, Singapore 117549, Singapore
| | - Ichiro Hirao
- Institute of Bioengineering and Bioimaging, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
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14
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Kimoto M, Hirao I. Genetic alphabet expansion technology by creating unnatural base pairs. Chem Soc Rev 2020; 49:7602-7626. [PMID: 33015699 DOI: 10.1039/d0cs00457j] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent advancements in the creation of artificial extra base pairs (unnatural base pairs, UBPs) are opening the door to a new research area, xenobiology, and genetic alphabet expansion technologies. UBPs that function as third base pairs in replication, transcription, and/or translation enable the site-specific incorporation of novel components into DNA, RNA, and proteins. Here, we describe the UBPs developed by three research teams and their application in PCR-based diagnostics, high-affinity DNA aptamer generation, site-specific labeling of RNAs, semi-synthetic organism creation, and unnatural-amino-acid-containing protein synthesis.
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Affiliation(s)
- Michiko Kimoto
- Institute of Bioengineering and Nanotechnology, A*STAR, Singapore.
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15
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Triskova I, Veznik J, Lacina K, Trnkova L. Dramatic changes in the electrochemical and spectroscopic behavior of DNA fragments induced by the loss of a single nucleotide. Bioelectrochemistry 2020; 134:107515. [PMID: 32200262 DOI: 10.1016/j.bioelechem.2020.107515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/13/2020] [Accepted: 03/13/2020] [Indexed: 12/17/2022]
Abstract
In this paper, the d(GCGAAGC) heptamer and the closely related d(GCGAGC) hexamer are examined via electrochemical (cyclic voltammetry) and spectroscopic (circular dichroism) methods. Dramatic changes in the CD spectroscopic and CV electrochemical properties, induced by the loss of only one single nucleotide (A), are detected. The CD spectra and native polyacrylamide gel electrophoresis (PAGE) confirmed structural changes taking place in the relevant chain-like oligodeoxynucleotide assemblies. Dedicated studies suggest that the heptamer (Hp) possesses a hairpin structure, whereas the hexamer (Hx) appears to be rather a duplex. Both of the structures exhibited completely different adsorption behavior at the hanging mercury drop electrode, and this factor was readily confirmed by means of elimination voltammetry with linear scan (EVLS). We established that the Hp hairpin (~-1300 mV), compared to the Hx duplex (~-1360 mV), is the thermodynamically favored electron acceptor. The adsorption isotherms were constructed based on the voltammetric peak height values, reflecting the reduction of the adenine (A) and cytosine (C) moieties as well as the oxidation of the 7,8-dihydroguanine (7,8-DHG) moieties. Finally, as revealed by the spectroscopic and electrochemical results, Hx forms a bimolecular antiparallel homo-duplex carrying both Watson-Crick base pairs (CG or GC) and mismatched edge-to-edge base pairs (GA or AG).
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Affiliation(s)
- Iveta Triskova
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Jakub Veznik
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Karel Lacina
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Libuse Trnkova
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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16
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Takahashi S, Sugimoto N. Stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells. Chem Soc Rev 2020; 49:8439-8468. [DOI: 10.1039/d0cs00594k] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review provides the biophysicochemical background and recent advances in stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells.
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Affiliation(s)
- Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST)
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17
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Kimoto M, Shermane Lim YW, Hirao I. Molecular affinity rulers: systematic evaluation of DNA aptamers for their applicabilities in ELISA. Nucleic Acids Res 2019; 47:8362-8374. [PMID: 31392985 PMCID: PMC6895277 DOI: 10.1093/nar/gkz688] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/09/2019] [Accepted: 07/30/2019] [Indexed: 12/15/2022] Open
Abstract
Many nucleic acid aptamers that bind to target molecules have been reported as antibody alternatives. However, while the affinities of aptamers vary widely, little is known about the relationship between the affinities and their applicabilities for practical use. Here, we developed molecular affinity rulers: a series of DNA aptamers with different affinities that bind to the same area of target molecules, to measure the aptamer and its device applicabilities. For the ruler preparation, we used high-affinity DNA aptamers containing a hydrophobic unnatural base (Ds) as the fifth base. By replacing Ds bases with A bases in Ds-DNA aptamers targeting VEGF165 and interferon-γ, we prepared two sets of DNA aptamers with dissociation constants (KD) ranging from 10−12 to 10−8 M. Using these molecular affinity rulers, we evaluated the sensitivity of DNA aptamers in ELISA (enzyme-linked immunosorbent assay), which showed the clear relationship between aptamer affinities and their detection sensitivities. In sandwich-type ELISA using combinations of aptamers and antibodies, aptamers with KD values lower than ∼10−9 M were required for sufficient sensitivities (limit of detection (LOD) < 10 pM) and signal intensities, but optimizations improved the lower-affinity aptamers’ applicabilities. These aptamer affinity rulers could be useful for evaluating and improving aptamer applicabilities.
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Affiliation(s)
- Michiko Kimoto
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
| | - Yun Wei Shermane Lim
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore.,NUS High School of Mathematics and Science, 20 Clementi Avenue 1, Singapore 129957, Singapore
| | - Ichiro Hirao
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #07-01, Singapore 138669, Singapore
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18
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Xu G, Zhao J, Liu N, Yang M, Zhao Q, Li C, Liu M. Structure-guided post-SELEX optimization of an ochratoxin A aptamer. Nucleic Acids Res 2019; 47:5963-5972. [PMID: 31062016 PMCID: PMC6582339 DOI: 10.1093/nar/gkz336] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/30/2019] [Accepted: 04/26/2019] [Indexed: 01/10/2023] Open
Abstract
SELEX is the cornerstone for aptamer research with broad applications in biosensors and medicine. To improve the affinity of selected aptamers, we propose a structure-guided post-SELEX approach, an optimization method based on the precise secondary structure of the aptamer–ligand complex. We demonstrate this approach using the Ochratoxin A (OTA) aptamer. Guided by the structure, we designed a new aptamer whose affinity is improved by more than 50-fold. We also determined the high-resolution NMR structure of the new aptamer-OTA complex and elucidated the discriminatory recognition mechanism of one atomic difference between two analogs, OTA and OTB. The aptamer forms an unusual hairpin structure containing an intramolecular triple helix, which is not seen in the previously determined aptamer complex. The π–π stacking, the hydrophobic interaction, hydrogen bonds and halogen bonds between OTA and the aptamer contribute to the recognition of OTA, and the halogen bonds play an important role in discriminating between OTA and OTB. Our results demonstrate that the structure-guided post-SELEX approach improves aptamers affinity. An improved OTA biosensor system might be developed using this new strategy.
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Affiliation(s)
- Guohua Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China
| | - Jiajing Zhao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China.,University of Chinese Academy of Sciences, Beijing 100029, P.R. China
| | - Na Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China.,University of Chinese Academy of Sciences, Beijing 100029, P.R. China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China
| | - Qiang Zhao
- University of Chinese Academy of Sciences, Beijing 100029, P.R. China.,State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P.R. China
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China.,University of Chinese Academy of Sciences, Beijing 100029, P.R. China
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R. China.,University of Chinese Academy of Sciences, Beijing 100029, P.R. China
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19
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Zheng J, Du Y, Wang H, Peng P, Shi L, Li T. Ultrastable Bimolecular G-Quadruplexes Programmed DNA Nanoassemblies for Reconfigurable Biomimetic DNAzymes. ACS NANO 2019; 13:11947-11954. [PMID: 31589020 DOI: 10.1021/acsnano.9b06029] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The relatively low stability and polymorphism of bimolecular G-quadruplexes (bi-G4s) are big difficulties that are faced in employing them to guide DNA assembly, as they are usually subject to a transformation into more stable tetramolecular or G-wire structures favored by K+ or Mg2+. Although bi-G4s benefit by additional duplex handles, a challenge remains in tailoring their intrinsic properties to resolve the above difficulties. Toward this challenge, here we engineer several ultrastable bi-G4s via replacing their nucleotide loops with special mini-hairpins, which consist of a GAA loop and a short GC-paired stem. Such a structural alteration favors the formation of G:C:G:C tetrads in the head-to-head folding topologies of bi-G4s and improves their thermal stability, with an increase in the melting temperature by up to 25 °C. It dramatically reduces their structural conversion into G-wires, verified by atomic force microscopy. These features enable the utilization of two well-chosen bi-G4s to shape a DNA nanotriangle into the desired framework nucleic acid (FNA) architectures such as "bowknot" and "butterfly" that are reversibly switched by the bi-G4s. On this basis, we further build a reconfigurable DNAzyme device to mimic the activation of human telomerase that is modulated by the G4 dimerization. Our designed ultrastable bi-G4s will offer a promising tool for dynamically manipulating intracellular DNA nanoassemblies with endogenous K+ and exploring the relationship between dimerization and function in some physiological processes.
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Affiliation(s)
- Jiao Zheng
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Yi Du
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Huihui Wang
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Pai Peng
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Lili Shi
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
| | - Tao Li
- Department of Chemistry , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , China
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20
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Oprzeska-Zingrebe EA, Smiatek J. Preferential Binding of Urea to Single-Stranded DNA Structures: A Molecular Dynamics Study. Biophys J 2019; 114:1551-1562. [PMID: 29642026 DOI: 10.1016/j.bpj.2018.02.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/12/2018] [Accepted: 02/12/2018] [Indexed: 01/06/2023] Open
Abstract
In nature, a wide range of biological processes such as transcription termination and intermolecular binding depend on the formation of specific DNA secondary and tertiary structures. These structures can be both stabilized or destabilized by different cosolutes coexisting with nucleic acids in the cellular environment. In our molecular dynamics simulation study, we investigate the binding of urea at different concentrations to short 7-nucleotide single-stranded DNA structures in aqueous solution. The local concentration of urea around a native DNA hairpin in comparison to an unfolded DNA conformation is analyzed by a preferential binding model in light of the Kirkwood-Buff theory. All our findings indicate a pronounced accumulation of urea around DNA that is driven by a combination of electrostatic and dispersion interactions and accomplished by a significant replacement of hydrating water molecules. The outcomes of our study can be regarded as a first step into a deeper mechanistic understanding toward cosolute-induced effects on nucleotide structures in general.
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Affiliation(s)
| | - Jens Smiatek
- Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany; Helmholtz Institute Münster: Ionics in Energy Storage, Forschungszentrum Jülich, Münster, Germany.
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21
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Towards Understanding of Polymorphism of the G-rich Region of Human Papillomavirus Type 52. Molecules 2019; 24:molecules24071294. [PMID: 30987050 PMCID: PMC6479982 DOI: 10.3390/molecules24071294] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 03/29/2019] [Accepted: 03/31/2019] [Indexed: 11/17/2022] Open
Abstract
The potential to affect gene expression via G-quadruplex stabilization has been extended to all domains of life, including viruses. Here, we investigate the polymorphism and structures of G-quadruplexes of the human papillomavirus type 52 with UV, CD and NMR spectroscopy and gel electrophoresis. We show that oligonucleotide with five G-tracts folds into several structures and that naturally occurring single nucleotide polymorphisms (SNPs) have profound effects on the structural polymorphism in the context of G-quadruplex forming propensity, conformational heterogeneity and folding stability. With help of SNP analysis, we were able to select one of the predominant forms, formed by G-rich sequence d(G₃TAG₃CAG₄ACACAG₃T). This oligonucleotide termed HPV52(1-4) adopts a three G-quartet snap back (3 + 1) type scaffold with four syn guanine residues, two edgewise loops spanning the same groove, a no-residue V loop and a propeller type loop. The first guanine residue is incorporated in the central G-quartet and all four-guanine residues from G4 stretch are included in the three quartet G-quadruplex core. Modification studies identified several structural elements that are important for stabilization of the described G-quadruplex fold. Our results expand set of G-rich targets in viral genomes and address the fundamental questions regarding folding of G-rich sequences.
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22
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Cunningham RM, Hickey AM, Wilson JW, Plakos KJI, DeRose VJ. Pt-induced crosslinks promote target enrichment and protection from serum nucleases. J Inorg Biochem 2018; 189:124-133. [PMID: 30245274 PMCID: PMC7703794 DOI: 10.1016/j.jinorgbio.2018.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/23/2018] [Accepted: 09/10/2018] [Indexed: 12/31/2022]
Abstract
Identifying the interactions of small molecules with biomolecules in complex cellular environments is a significant challenge. As one important example, despite being widely used for decades, much is still not understood regarding the cellular targets of Pt(II)-based anticancer drugs. In this study we introduce a novel method for isolation of Pt(II)-bound biomolecules using a DNA hybridization pull-down approach. Using a modified Pt reagent, click-ligation of a DNA oligonucleotide to both a Pt(II)-bound DNA hairpin and bovine serum albumin (BSA) are demonstrated. Subsequent hybridization to a biotin-labeled oligonucleotide allows for efficient isolation of Pt(II)-bound species by streptavidin pulldown. We also find that platinated bovine serum albumin readily crosslinks to DNA in the absence of click ligation, and that a fraction of BSA-bound Pt(II) can transfer to DNA over time. Interestingly, in in vitro studies, fragmented mammalian DNA that is crosslinked to BSA through Pt(II) exhibits significantly increased protection from degradation by serum nucleases.
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Affiliation(s)
- Rachael M Cunningham
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Anna M Hickey
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA
| | - Jesse W Wilson
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Kory J I Plakos
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Victoria J DeRose
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
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23
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Genetic Alphabet Expansion Provides Versatile Specificities and Activities of Unnatural-Base DNA Aptamers Targeting Cancer Cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 14:158-170. [PMID: 30594072 PMCID: PMC6307347 DOI: 10.1016/j.omtn.2018.11.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/26/2018] [Accepted: 11/15/2018] [Indexed: 11/25/2022]
Abstract
The potential of genetic alphabet expansion technologies using artificial extra base pairs (unnatural base pairs) has been rapidly expanding and increasing. We present that the hydrophobic unnatural base, 7-(2-thienyl)imidazo[4,5-b]pyridine (Ds), which acts as a fifth letter in a DNA library, provides a series of high-affinity DNA aptamers with versatile binding specificities and activities to cancer cells. These Ds-containing DNA aptamers were generated by a method called cell-ExSELEX to target three breast cancer cell lines: MCF7, MDA-MB-231, and T-47D. Aptamer 14A-MCF7, which targets MCF7 cells, specifically binds to MCF7 cells, but not other cancer cell lines. Aptamer 07-MB231, which targets MDA-MB-231 cells, binds to a series of metastatic bone and lung cancer cell lines. Aptamer 05-MB231 targets MDA-MB-231 cells, but it also binds to all of the cancer and leukemia cell lines that we examined. None of these aptamers bind to normal cell lines, such as MCF10A and HUVEC. In addition, aptamers 14A-MCF7 and 05-MB231 are internalized within the cancer cells, and aptamer 05-MB231 possesses anti-proliferative properties against most cancer cell lines that we examined. These aptamers and the generation method are broadly applicable to cancer cell imaging, biomarker discovery, cancer cell profiling, anti-cancer therapies, and drug delivery systems.
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24
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Yamaoki Y, Kiyoishi A, Miyake M, Kano F, Murata M, Nagata T, Katahira M. The first successful observation of in-cell NMR signals of DNA and RNA in living human cells. Phys Chem Chem Phys 2018; 20:2982-2985. [PMID: 29022027 DOI: 10.1039/c7cp05188c] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In order to understand intracellular biological events, information on the structure, dynamics and interaction of proteins and nucleic acids in living cells is of crucial importance. In-cell NMR is a promising method to obtain this information. Although NMR signals of proteins in human cells have been reported, those of nucleic acids were reported only in Xenopus laevis oocytes, i.e., not in human cells. Here, DNA and RNA were introduced into human cells by means of pore formation by bacterial toxin streptolysin O and subsequent resealing. Then, NMR signals of DNA and RNA were successfully observed for the first time in living human cells. The observed signals directly suggested the formation of DNA and RNA hairpin structures in living human cells.
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Affiliation(s)
- Yudai Yamaoki
- Institute of Advanced Energy, Kyoto University, Kyoto 611-0011, Japan.
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25
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Oprzeska-Zingrebe EA, Meyer S, Roloff A, Kunte HJ, Smiatek J. Influence of compatible solute ectoine on distinct DNA structures: thermodynamic insights into molecular binding mechanisms and destabilization effects. Phys Chem Chem Phys 2018; 20:25861-25874. [DOI: 10.1039/c8cp03543a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We study ectoine-induced destabilization effects on DNA hairpins by a combination of atomistic molecular dynamics simulations, experiments, and theoretical approaches.
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Affiliation(s)
| | - Susann Meyer
- Federal Institute for Materials Research and Testing (BAM)
- D-12205 Berlin
- Germany
- Institute of Biochemistry and Biology
- University of Potsdam
| | - Alexander Roloff
- Federal Institute for Materials Research and Testing (BAM)
- D-12489 Berlin
- Germany
| | - Hans-Jörg Kunte
- Federal Institute for Materials Research and Testing (BAM)
- D-12205 Berlin
- Germany
| | - Jens Smiatek
- Institute for Computational Physics
- University of Stuttgart
- D-70569 Stuttgart
- Germany
- Helmholtz Institute Münster: Ionics in Energy Storage (HI MS IEK-12)
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26
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Röthlisberger P, Gasse C, Hollenstein M. Nucleic Acid Aptamers: Emerging Applications in Medical Imaging, Nanotechnology, Neurosciences, and Drug Delivery. Int J Mol Sci 2017; 18:E2430. [PMID: 29144411 PMCID: PMC5713398 DOI: 10.3390/ijms18112430] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 12/25/2022] Open
Abstract
Recent progresses in organic chemistry and molecular biology have allowed the emergence of numerous new applications of nucleic acids that markedly deviate from their natural functions. Particularly, DNA and RNA molecules-coined aptamers-can be brought to bind to specific targets with high affinity and selectivity. While aptamers are mainly applied as biosensors, diagnostic agents, tools in proteomics and biotechnology, and as targeted therapeutics, these chemical antibodies slowly begin to be used in other fields. Herein, we review recent progress on the use of aptamers in the construction of smart DNA origami objects and MRI and PET imaging agents. We also describe advances in the use of aptamers in the field of neurosciences (with a particular emphasis on the treatment of neurodegenerative diseases) and as drug delivery systems. Lastly, the use of chemical modifications, modified nucleoside triphosphate particularly, to enhance the binding and stability of aptamers is highlighted.
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Affiliation(s)
- Pascal Röthlisberger
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris CEDEX 15, France.
| | - Cécile Gasse
- Institute of Systems & Synthetic Biology, Xenome Team, 5 rue Henri Desbruères Genopole Campus 1, University of Evry, F-91030 Evry, France.
| | - Marcel Hollenstein
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris CEDEX 15, France.
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Ghosh S, Mallick S, Das U, Verma A, Pal U, Chatterjee S, Nandy A, Saha KD, Maiti NC, Baishya B, Suresh Kumar G, Gmeiner WH. Curcumin stably interacts with DNA hairpin through minor groove binding and demonstrates enhanced cytotoxicity in combination with FdU nucleotides. Biochim Biophys Acta Gen Subj 2017; 1862:485-494. [PMID: 29107813 DOI: 10.1016/j.bbagen.2017.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 10/11/2017] [Accepted: 10/26/2017] [Indexed: 12/12/2022]
Abstract
We report, based on biophysical studies and molecular mechanical calculations that curcumin binds DNA hairpin in the minor groove adjacent to the loop region forming a stable complex. UV-Vis and fluorescence spectroscopy indicated interaction of curcumin with DNA hairpin. In this novel binding motif, two ɣ H of curcumin heptadiene chain are closely positioned to the A16-H8 and A17-H8, while G12-H8 is located in the close proximity of curcumin α H. Molecular dynamics (MD) simulations suggest, the complex is stabilized by noncovalent forces including; π-π stacking, H-bonding and hydrophobic interactions. Nuclear magnetic resonance (NMR) spectroscopy in combination with molecular dynamics simulations indicated curcumin is bound in the minor groove, while circular dichroism (CD) spectra suggested minute enhancement in base stacking and a little change in DNA helicity, without significant conformational change of DNA hairpin structure. The DNA:curcumin complex formed with FdU nucleotides rather than Thymidine, demonstrated enhanced cytotoxicity towards oral cancer cells relative to the only FdU substituted hairpin. Fluorescence co-localization demonstrated stability of the complex in biologically relevant conditions, including its cellular uptake. Acridine orange/EtBr staining further confirmed the enhanced cytotoxic effects of the complex, suggesting apoptosis as mode of cell death. Thus, curcumin can be noncovalently complexed to small DNA hairpin for cellular delivery and the complex showed increased cytotoxicity in combination with FdU nucleotides, demonstrating its potential for advanced cancer therapy.
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Affiliation(s)
- Supratim Ghosh
- Chittaranjan National Cancer Institute, Kolkata, WB 700026, India.
| | - Sumana Mallick
- CSIR-Indian Institute of Chemical Biology, Kolkata, WB 700032, India
| | - Upasana Das
- Chittaranjan National Cancer Institute, Kolkata, WB 700026, India
| | - Ajay Verma
- Centre of BioMedical Research, Lucknow, UP 226014, India
| | - Uttam Pal
- CSIR-Indian Institute of Chemical Biology, Kolkata, WB 700032, India
| | | | - Abhishek Nandy
- CSIR-Indian Institute of Chemical Biology, Kolkata, WB 700032, India
| | - Krishna D Saha
- CSIR-Indian Institute of Chemical Biology, Kolkata, WB 700032, India
| | | | - Bikash Baishya
- Centre of BioMedical Research, Lucknow, UP 226014, India
| | - G Suresh Kumar
- CSIR-Indian Institute of Chemical Biology, Kolkata, WB 700032, India
| | - William H Gmeiner
- Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Hirao I, Kimoto M, Lee KH. DNA aptamer generation by ExSELEX using genetic alphabet expansion with a mini-hairpin DNA stabilization method. Biochimie 2017; 145:15-21. [PMID: 28916151 DOI: 10.1016/j.biochi.2017.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022]
Abstract
A novel aptamer generation method to greatly augment the affinity and stability of DNA aptamers was developed by genetic alphabet expansion combined with mini-hairpin DNA technology. The genetic alphabet expansion increases the physicochemical and structural diversities of DNA aptamers by introducing extra components, unnatural bases, as a fifth base, allowing for the enhancement of DNA aptamer affinities. Furthermore, the mini-hairpin DNA technology stabilizes DNA aptamers against nuclease digestion and thermal denaturation, by introducing an extraordinarily stable mini-hairpin DNA containing a GCGAAGC sequence. This novel method provides stabilized high-affinity DNA aptamers for diagnostic and therapeutic applications.
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Affiliation(s)
- Ichiro Hirao
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #09-01, Singapore, 138669, Singapore.
| | - Michiko Kimoto
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #09-01, Singapore, 138669, Singapore
| | - Kyung Hyun Lee
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #09-01, Singapore, 138669, Singapore
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29
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Matsunaga KI, Kimoto M, Hirao I. High-Affinity DNA Aptamer Generation Targeting von Willebrand Factor A1-Domain by Genetic Alphabet Expansion for Systematic Evolution of Ligands by Exponential Enrichment Using Two Types of Libraries Composed of Five Different Bases. J Am Chem Soc 2016; 139:324-334. [PMID: 27966933 DOI: 10.1021/jacs.6b10767] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The novel evolutionary engineering method ExSELEX (genetic alphabet expansion for systematic evolution of ligands by exponential enrichment) provides high-affinity DNA aptamers that specifically bind to target molecules, by introducing an artificial hydrophobic base analogue as a fifth component into DNA aptamers. Here, we present a newer version of ExSELEX, using a library with completely randomized sequences consisting of five components: four natural bases and one unnatural hydrophobic base, 7-(2-thienyl)imidazo[4,5-b]pyridine (Ds). In contrast to the limited number of Ds-containing sequence combinations in our previous library, the increased complexity of the new randomized library could improve the success rates of high-affinity aptamer generation. To this end, we developed a sequencing method for each clone in the enriched library after several rounds of selection. Using the improved library, we generated a Ds-containing DNA aptamer targeting von Willebrand factor A1-domain (vWF) with significantly higher affinity (KD = 75 pM), relative to those generated by the initial version of ExSELEX, as well as that of the known DNA aptamer consisting of only the natural bases. In addition, the Ds-containing DNA aptamer was stabilized by introducing a mini-hairpin DNA resistant to nucleases, without any loss of affinity (KD = 61 pM). This new version is expected to consistently produce high-affinity DNA aptamers.
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Affiliation(s)
- Ken-Ichiro Matsunaga
- Institute of Bioengineering and Nanotechnology , 31 Biopolis Way, The Nanos, #04-01, 138669 Singapore.,TagCyx Biotechnologies , 1-6-126 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.,RIKEN Center for Life Science Technologies , 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Michiko Kimoto
- Institute of Bioengineering and Nanotechnology , 31 Biopolis Way, The Nanos, #04-01, 138669 Singapore.,TagCyx Biotechnologies , 1-6-126 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.,RIKEN Center for Life Science Technologies , 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Ichiro Hirao
- Institute of Bioengineering and Nanotechnology , 31 Biopolis Way, The Nanos, #04-01, 138669 Singapore.,TagCyx Biotechnologies , 1-6-126 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.,RIKEN Center for Life Science Technologies , 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
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Wang J, Dong P, Wu W, Pan X, Liang X. High-throughput thermal stability assessment of DNA hairpins based on high resolution melting. J Biomol Struct Dyn 2016; 36:1-13. [PMID: 28024437 DOI: 10.1080/07391102.2016.1266967] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
On the basis of high-resolution melting, a high-throughput approach to measure melting temperatures (Tms) of short DNA hairpins was developed. With this method, Tms of thousands of triloop, tetraloop, and pentaloop hairpins involving various loop sequences and various closing base pairs (cbp) were obtained in hours. The stability of triloop hairpins decreased with the change of cbp (5'-3') in the order of c-g > g-c > t-a ≥ a-t, showing that the cbp of 5'-Pyr-Pur-3' (Pyr = pyrimidine, Pur = purine) contributed more stability than 5'-Pur-Pyr-3'. For tetraloop hairpins, GNNA, GNAB, and CNNG (N = A, G, C, or T; B = G, C, or T) were found to be highly stable irrespective of the cbp type. TNNA was also stable in both g-c and a-t families, while CGNA only in the c-g family. Pentaloop hairpins of cTGNAGg, cGNYNAg (Y = T or C) and cCGNNAg were exceptionally stable motifs. In most cases, pyrimidine-rich loops were more favorable to stabilize the whole structure than purine-rich ones. The present approach showed a good performance in assessing the thermal stability of large amounts of DNA hairpins comprehensively. These data are useful to understand the sequence dependence of the stability of DNA secondary structures and promising to improve the structure simulation by consummating basic databases.
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Affiliation(s)
- Jing Wang
- a College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Ping Dong
- a College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Wei Wu
- a College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Xiaoming Pan
- a College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Xingguo Liang
- a College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
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Zhang Q, Lv H, Wang L, Chen M, Li F, Liang C, Yu Y, Jiang F, Lu A, Zhang G. Recent Methods for Purification and Structure Determination of Oligonucleotides. Int J Mol Sci 2016; 17:E2134. [PMID: 27999357 PMCID: PMC5187934 DOI: 10.3390/ijms17122134] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 12/13/2016] [Accepted: 12/14/2016] [Indexed: 12/14/2022] Open
Abstract
Aptamers are single-stranded DNA or RNA oligonucleotides that can interact with target molecules through specific three-dimensional structures. The excellent features, such as high specificity and affinity for target proteins, small size, chemical stability, low immunogenicity, facile chemical synthesis, versatility in structural design and engineering, and accessible for site-specific modifications with functional moieties, make aptamers attractive molecules in the fields of clinical diagnostics and biopharmaceutical therapeutics. However, difficulties in purification and structural identification of aptamers remain a major impediment to their broad clinical application. In this mini-review, we present the recently attractive developments regarding the purification and identification of aptamers. We also discuss the advantages, limitations, and prospects for the major methods applied in purifying and identifying aptamers, which could facilitate the application of aptamers.
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MESH Headings
- Aptamers, Nucleotide/chemistry
- Chromatography, High Pressure Liquid/methods
- Chromatography, Ion Exchange/methods
- Chromatography, Reverse-Phase/methods
- Crystallography, X-Ray/methods
- DNA, Single-Stranded/chemistry
- DNA, Single-Stranded/ultrastructure
- Electrophoresis, Gel, Two-Dimensional/methods
- Nuclear Magnetic Resonance, Biomolecular/methods
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Affiliation(s)
- Qiulong Zhang
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Huanhuan Lv
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Lili Wang
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Man Chen
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Fangfei Li
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Chao Liang
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Yuanyuan Yu
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Feng Jiang
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- The State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Aiping Lu
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
| | - Ge Zhang
- Institute of Integrated Bioinformedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University (HKBU), Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, HKBU (Haimen) Institute of Science and Technology, Haimen 226100, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China.
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Triskova I, Fiala R, Trnkova L. Redox Processes of Guanine Moieties in DNA Heptamers Related to Hydrogen Evolution. ELECTROANAL 2016. [DOI: 10.1002/elan.201600321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Iveta Triskova
- Department of Chemistry; Faculty of Science; Masaryk University; Kamenice 5 CZ-625 00 Brno Czech Republic
| | - Radovan Fiala
- CEITEC-Central European Institute of Technology; Masaryk University; Kamenice 5 CZ-625 00 Brno Czech Republic
- National Centre for Biomolecular Research; Faculty of Science; Masaryk University; Kamenice 5 CZ-625 00 Brno Czech Republic
| | - Libuse Trnkova
- Department of Chemistry; Faculty of Science; Masaryk University; Kamenice 5 CZ-625 00 Brno Czech Republic
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Kimoto M, Nakamura M, Hirao I. Post-ExSELEX stabilization of an unnatural-base DNA aptamer targeting VEGF165 toward pharmaceutical applications. Nucleic Acids Res 2016; 44:7487-94. [PMID: 27387284 PMCID: PMC5009754 DOI: 10.1093/nar/gkw619] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 06/30/2016] [Indexed: 01/14/2023] Open
Abstract
A new technology, genetic alphabet expansion using artificial bases (unnatural bases), has created high-affinity DNA ligands (aptamers) that specifically bind to target proteins by ExSELEX (genetic alphabet Expansion for Systematic Evolution of Ligands by EXponential enrichment). We recently found that the unnatural-base DNA aptamers can be stabilized against nucleases, by introducing an extraordinarily stable, unique hairpin DNA (mini-hairpin DNA) and by reinforcing the stem region with G–C pairs. Here, to establish this aptamer generation method, we examined the stabilization of a high-affinity anti-VEGF165 unnatural-base DNA aptamer. The stabilized aptamers displayed significantly increased thermal and nuclease stabilities, and furthermore, exhibited higher affinity to the target. As compared to the well-known anti-VEGF165 RNA aptamer, pegaptanib (Macugen), our aptamers did not require calcium ions for binding to VEGF165. Biological experiments using cultured cells revealed that our stabilized aptamers efficiently inhibited the interaction between VEGF165 and its receptor, with the same or slightly higher efficiency than that of the pegaptanib RNA aptamer. The development of cost-effective and calcium ion-independent high-affinity anti-VEGF165 DNA aptamers encourages further progress in diagnostic and therapeutic applications. In addition, the stabilization process provided additional information about the key elements required for aptamer binding to VEGF165.
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Affiliation(s)
- Michiko Kimoto
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #04-01, 138669, Singapore RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan TagCyx Biotechnologies, 1-6-126 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan PRESTO, JST, Honcho, Kawaguchi-shi, Saitama 332-0012, Japan
| | - Mana Nakamura
- RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan Department of Medical Life Science, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| | - Ichiro Hirao
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #04-01, 138669, Singapore RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan TagCyx Biotechnologies, 1-6-126 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
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34
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Switching central trinucleotide sequences of DNA heptamer regulates adsorption on mercury electrode. MONATSHEFTE FUR CHEMIE 2016. [DOI: 10.1007/s00706-016-1689-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Architecture of high-affinity unnatural-base DNA aptamers toward pharmaceutical applications. Sci Rep 2015; 5:18478. [PMID: 26690672 PMCID: PMC4686876 DOI: 10.1038/srep18478] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 11/19/2015] [Indexed: 11/08/2022] Open
Abstract
We present a remodeling method for high-affinity unnatural-base DNA aptamers to augment their thermal stability and nuclease resistance, for use as drug candidates targeting specific proteins. Introducing a unique mini-hairpin DNA provides robust stability to unnatural-base DNA aptamers generated by SELEX using genetic alphabet expansion, without reducing their high affinity. By this method, >80% of the remodeled DNA aptamer targeting interferon-γ (KD of 33 pM) survived in human serum at 37 °C after 3 days under our experimental conditions, and sustainably inhibited the biological activity of interferon-γ.
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36
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Marušič M, Plavec J. The Effect of DNA Sequence Directionality on G-Quadruplex Folding. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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37
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Marušič M, Plavec J. The Effect of DNA Sequence Directionality on G‐Quadruplex Folding. Angew Chem Int Ed Engl 2015; 54:11716-9. [DOI: 10.1002/anie.201505348] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/20/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Maja Marušič
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia)
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia)
- EN‐FIST Center of Excellence, 1000 Ljubljana (Slovenia)
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana (Slovenia)
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38
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Nishio M, Umezawa Y, Fantini J, Weiss MS, Chakrabarti P. CH-π hydrogen bonds in biological macromolecules. Phys Chem Chem Phys 2015; 16:12648-83. [PMID: 24836323 DOI: 10.1039/c4cp00099d] [Citation(s) in RCA: 335] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This is a sequel to the previous Perspective "The CH-π hydrogen bond in chemistry. Conformation, supramolecules, optical resolution and interactions involving carbohydrates", which featured in a PCCP themed issue on "Weak Hydrogen Bonds - Strong Effects?": Phys. Chem. Chem. Phys., 2011, 13, 13873-13900. Evidence that weak hydrogen bonds play an enormously important role in chemistry and biochemistry has now accumulated to an extent that the rigid classical concept of hydrogen bonds formulated by Pauling needs to be seriously revised and extended. The concept of a more generalized hydrogen bond definition is indispensable for understanding the folding mechanisms of proteins. The CH-π hydrogen bond, a weak molecular force occurring between a soft acid CH and a soft base π-electron system, among all is one of the most important and plays a functional role in defining the conformation and stability of 3D structures as well as in many molecular recognition events. This concept is also valuable in structure-based drug design efforts. Despite their frequent occurrence in organic molecules and bio-molecules, the importance of CH-π hydrogen bonds is still largely unknown to many chemists and biochemists. Here we present a review that deals with the evidence, nature, characteristics and consequences of the CH-π hydrogen bond in biological macromolecules (proteins, nucleic acids, lipids and polysaccharides). It is hoped that the present Perspective will show the importance of CH-π hydrogen bonds and stimulate interest in the interactions of biological macromolecules, one of the most fascinating fields in bioorganic chemistry. Implication of this concept is enormous and valuable in the scientific community.
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Affiliation(s)
- Motohiro Nishio
- The CHPI Institute, 705-6-338, Minamioya, Machida-shi, Tokyo 194-0031, Japan.
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Ng KS, Lam SL. NMR proton chemical shift prediction of C·C mismatches in B-DNA. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 252:87-93. [PMID: 25681800 DOI: 10.1016/j.jmr.2015.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 01/09/2015] [Accepted: 01/11/2015] [Indexed: 05/15/2023]
Abstract
Accurate prediction of DNA chemical shifts facilitates resonance assignment and allows recognition of different conformational features. Based on the nearest neighbor model and base pair replacement approach, we have determined a set of triplet chemical shift values and correction factors for predicting the proton chemical shifts of B-DNA containing an internal C·C mismatch. Our results provide a reliable chemical shift prediction with an accuracy of 0.07 ppm for non-labile protons and 0.09 ppm for labile protons. In addition, we have also shown that the correction factors for C·C mismatches can be used interchangeably with those for T·T mismatches. As a result, we have generalized a set of correction factors for predicting the flanking residue chemical shifts of pyrimidine·pyrimidine mismatches.
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Affiliation(s)
- Kui Sang Ng
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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40
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Pilarova I, Kejnovska I, Vorlickova M, Trnkova L. Dynamic Structures of DNA Heptamers with Different Central Trinucleotide Sequences Studied by Electrochemical and Spectral Methods. ELECTROANAL 2014. [DOI: 10.1002/elan.201400288] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Northam MR, Moore EA, Mertz TM, Binz SK, Stith CM, Stepchenkova EI, Wendt KL, Burgers PMJ, Shcherbakova PV. DNA polymerases ζ and Rev1 mediate error-prone bypass of non-B DNA structures. Nucleic Acids Res 2013; 42:290-306. [PMID: 24049079 PMCID: PMC3874155 DOI: 10.1093/nar/gkt830] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
DNA polymerase ζ (Pol ζ) and Rev1 are key players in translesion DNA synthesis. The error-prone Pol ζ can also participate in replication of undamaged DNA when the normal replisome is impaired. Here we define the nature of the replication disturbances that trigger the recruitment of error-prone polymerases in the absence of DNA damage and describe the specific roles of Rev1 and Pol ζ in handling these disturbances. We show that Pol ζ/Rev1-dependent mutations occur at sites of replication stalling at short repeated sequences capable of forming hairpin structures. The Rev1 deoxycytidyl transferase can take over the stalled replicative polymerase and incorporate an additional 'C' at the hairpin base. Full hairpin bypass often involves template-switching DNA synthesis, subsequent realignment generating multiply mismatched primer termini and extension of these termini by Pol ζ. The postreplicative pathway dependent on polyubiquitylation of proliferating cell nuclear antigen provides a backup mechanism for accurate bypass of these sequences that is primarily used when the Pol ζ/Rev1-dependent pathway is inactive. The results emphasize the pivotal role of noncanonical DNA structures in mutagenesis and reveal the long-sought-after mechanism of complex mutations that represent a unique signature of Pol ζ.
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Affiliation(s)
- Matthew R Northam
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68118, USA and Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
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Kwok CK, Lam SL. NMR proton chemical shift prediction of T·T mismatches in B-DNA duplexes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 234:184-9. [PMID: 23892104 DOI: 10.1016/j.jmr.2013.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/24/2013] [Accepted: 06/28/2013] [Indexed: 05/15/2023]
Abstract
A proton chemical shift prediction scheme for B-DNA duplexes containing a T·T mismatch has been established. The scheme employs a set of T·T mismatch triplet chemical shift values, 5'- and 3'-correction factors extracted from reference sequences, and also the B-DNA chemical shift values predicted by Altona et al. The prediction scheme was tested by eight B-DNA duplexes containing T·T mismatches. Based on 560 sets of predicted and experimental proton chemical shift values, the overall prediction accuracy for non-labile protons was determined to be 0.07 ppm with an excellent correlation coefficient of 0.9996. In addition, the prediction accuracy for 96 sets of labile protons was found to be 0.22 ppm with a correlation coefficient of 0.9961. The prediction scheme developed herein can facilitate resonance assignments of B-DNA duplexes containing T·T mismatches and be generalized for the chemical shift prediction of other DNA mismatches. Our chemical shift data will also be useful for establishing structure-chemical shift information in B-DNA containing mismatches.
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Affiliation(s)
- Chun Kit Kwok
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Au RY, Ng KS, Chi LM, Lam SL. Effect of an abasic site on strand slippage in DNA primer-templates. J Phys Chem B 2012; 116:14781-7. [PMID: 23215233 DOI: 10.1021/jp308759k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An abasic site is the most common lesion in DNA. It is also an intermediate product formed during base excision repair. Previously, we demonstrated that strand slippage can occur in primer-template model systems containing any kind of natural templating bases, suggesting deletion and expansion errors are possible in any kind of sequences during DNA replication. In this study, nuclear magnetic resonance spectroscopic investigations have been performed to study the intrinsic effect of a templating abasic residue on strand slippage in primer-template models. A DNA hairpin model system containing an abasic site and a 5'-overhang region was used to mimic the situation that a dNTP has just been incorporated opposite the abasic site. Our results show that, after dNTP incorporation, strand slippage occurs regardless of the type of terminal base pair formed. Compared to natural templating bases, abasic sites possess a higher slippage propensity, implicating a higher chance of expansion or deletion errors during DNA replication.
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Affiliation(s)
- Ring Yan Au
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Rubin Y, Belous L, Evstigneev M. On the a priori possibility of the formation of hexameric mini-hairpin d(GCGAGC) in solution. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.05.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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45
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Hunter RS, van Mourik T. DNA base stacking: The stacked uracil/uracil and thymine/thymine minima. J Comput Chem 2012; 33:2161-72. [DOI: 10.1002/jcc.23052] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/01/2012] [Accepted: 06/04/2012] [Indexed: 01/24/2023]
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del Mundo IMA, Siters KE, Fountain MA, Morrow JR. Structural basis for bifunctional zinc(II) macrocyclic complex recognition of thymine bulges in DNA. Inorg Chem 2012; 51:5444-57. [PMID: 22507054 DOI: 10.1021/ic3004245] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The zinc(II) complex of 1-(4-quinoylyl)methyl-1,4,7,10-tetraazacyclododecane (cy4q) binds selectively to thymine bulges in DNA and to a uracil bulge in RNA. Binding constants are in the low-micromolar range for thymine bulges in the stems of hairpins, for a thymine bulge in a DNA duplex, and for a uracil bulge in an RNA hairpin. Binding studies of Zn(cy4q) to a series of hairpins containing thymine bulges with different flanking bases showed that the complex had a moderate selectivity for thymine bulges with neighboring purines. The dissociation constants of the most strongly bound Zn(cy4q)-DNA thymine bulge adducts were 100-fold tighter than similar sequences with fully complementary stems or than bulges containing cytosine, guanine, or adenine. In order to probe the role of the pendent group, three additional zinc(II) complexes containing 1,4,7,10-tetraazacyclododecane (cyclen) with aromatic pendent groups were studied for binding to DNA including 1-(2-quinolyl)methyl-1,4,7,10-tetraazacyclododecane (cy2q), 1-(4-biphenyl)methyl-1,4,7,10-tetraazacyclododecane (cybp), and 5-(1,4,7,10-tetraazacyclododecan-1-ylsulfonyl)-N,N-dimethylnaphthalen-1-amine (dsc). The Zn(cybp) complex binds with moderate affinity but little selectivity to DNA hairpins with thymine bulges and to DNA lacking bulges. Similarly, Zn(dsc) binds weakly both to thymine bulges and hairpins with fully complementary stems. The zinc(II) complex of cy2q has the 2-quinolyl moiety bound to the Zn(II) center, as shown by (1)H NMR spectroscopy and pH-potentiometric titrations. As a consequence, only weak (500 μM) binding is observed to DNA with no appreciable selectivity. An NMR structure of a thymine-bulge-containing hairpin shows that the thymine is extrahelical but rotated toward the major groove. NMR data for Zn(cy4q) bound to DNA containing a thymine bulge is consistent with binding of the zinc(II) complex to the thymine N3(-) and stacking of the quinoline on top of the thymine. The thymine-bulge bound zinc(II) complex is pointed into the major groove, and there are interactions with the guanine positioned 5' to the thymine bulge.
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Affiliation(s)
- Imee Marie A del Mundo
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
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Souissi I, Ladam P, Cognet JAH, Le Coquil S, Varin-Blank N, Baran-Marszak F, Metelev V, Fagard R. A STAT3-inhibitory hairpin decoy oligodeoxynucleotide discriminates between STAT1 and STAT3 and induces death in a human colon carcinoma cell line. Mol Cancer 2012; 11:12. [PMID: 22423663 PMCID: PMC3325846 DOI: 10.1186/1476-4598-11-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 03/16/2012] [Indexed: 01/09/2023] Open
Abstract
Background The Signal Transducer and Activator of Transcription 3 (STAT3) is activated in tumor cells, and STAT3-inhibitors are able to induce the death of those cells. Decoy oligodeoxynucleotides (dODNs), which bind to the DNA Binding Domain (DBD) of STAT3, are efficient inhibitors. However, they also inhibit STAT1, whose activity is essential not only to resistance to pathogens, but also to cell growth inhibition and programmed cell death processes. The aim of this study was to design STAT3-specific dODNs which do not affect STAT1-mediated processes. Results New dODNs with a hairpin (hpdODNs) were designed. Modifications were introduced, based on the comparison of STAT3- and STAT1-DBD interactions with DNA using 3D structural analyses. The designed hpdODNs were tested for their ability to inhibit STAT3 but not STAT1 by determining: i) cell death in the active STAT3-dependent SW480 colon carcinoma cell line, ii) absence of inhibition of interferon (IFN) γ-dependent cell death, iii) expression of STAT1 targets, and iv) nuclear location of STAT3 and STAT1. One hpdODN was found to efficiently induce the death of SW480 cells without interfering with IFNγ-activated STAT1. This hpdODN was found in a complex with STAT3 but not with STAT1 using an original in-cell pull-down assay; this hpdODN also did not inhibit IFNγ-induced STAT1 phosphorylation, nor did it inhibit the expression of the STAT1-target IRF1. Furthermore, it prevented the nuclear transfer of STAT3 but not that of IFNγ-activated STAT1. Conclusions Comparative analyses at the atomic level revealed slight differences in STAT3 and STAT1 DBDs' interaction with their DNA target. These were sufficient to design a new discriminating hpdODN that inhibits STAT3 and not STAT1, thereby inducing tumor cell death without interfering with STAT1-dependent processes. Preferential interaction with STAT3 depends on oligodeoxynucleotide sequence modifications but might also result from DNA shape changes, known to modulate protein/DNA interactions. The finding of a STAT3-specific hpdODN establishes the first rational basis for designing STAT3 DBD-specific inhibitors.
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48
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Chi LM, Lam SL. Sequence context effect on strand slippage in natural DNA primer-templates. J Phys Chem B 2012; 116:1999-2007. [PMID: 22304666 DOI: 10.1021/jp211666k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Strand slippage has been found to occur in primer-templates containing a templating thymine, cytosine, and guanine, leading to the formation of misaligned structures with a single-nucleotide bulge. If remained in the active site of low-fidelity polymerases during DNA replication, these misaligned structures can ultimately bring about deletion mutations. In this study, we performed NMR investigations on primer-template models containing a templating adenine. Similar to our previous results on guanine, adenine templates are also less prone to strand slippage than pyrimidine templates. Misalignment occurs only in primer-templates that form a terminal C·G or G·C base pair. Together with our previous findings on thymine, cytosine, and guanine templates, the present study reveals strand slippage can occur in any kind of natural templating bases during DNA replication, providing insights into the origin of mutation hotspots in natural DNA sequences. In addition to the type of incoming base upon misincorporation, the propensity of strand slippage in primer-templates depends also on the type of templating base, its upstream and downstream bases.
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Affiliation(s)
- Lai Man Chi
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Kannan S, Zacharias M. Role of the closing base pair for d(GCA) hairpin stability: free energy analysis and folding simulations. Nucleic Acids Res 2011; 39:8271-80. [PMID: 21724608 PMCID: PMC3201870 DOI: 10.1093/nar/gkr541] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/11/2011] [Accepted: 06/13/2011] [Indexed: 01/17/2023] Open
Abstract
Hairpin loops belong to the most important structural motifs in folded nucleic acids. The d(GNA) sequence in DNA can form very stable trinucleotide hairpin loops depending, however, strongly on the closing base pair. Replica-exchange molecular dynamics (REMD) were employed to study hairpin folding of two DNA sequences, d(gcGCAgc) and d(cgGCAcg), with the same central loop motif but different closing base pairs starting from single-stranded structures. In both cases, conformations of the most populated conformational cluster at the lowest temperature showed close agreement with available experimental structures. For the loop sequence with the less stable G:C closing base pair, an alternative loop topology accumulated as second most populated conformational state indicating a possible loop structural heterogeneity. Comparative-free energy simulations on induced loop unfolding indicated higher stability of the loop with a C:G closing base pair by ~3 kcal mol(-1) (compared to a G:C closing base pair) in very good agreement with experiment. The comparative energetic analysis of sampled unfolded, intermediate and folded conformational states identified electrostatic and packing interactions as the main contributions to the closing base pair dependence of the d(GCA) loop stability.
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Affiliation(s)
- Srinivasaraghavan Kannan
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale) and Physik-Department T38, Technische Universität München, 85747 Garching, Germany
| | - Martin Zacharias
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale) and Physik-Department T38, Technische Universität München, 85747 Garching, Germany
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Gmeiner WH, Salsbury F, Olsen CM, Marky LA. The stability of a model substrate for topoisomerase 1-mediated DNA religation depends on the presence of mismatched base pairs. J Nucleic Acids 2011; 2011:631372. [PMID: 21904666 PMCID: PMC3166759 DOI: 10.4061/2011/631372] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/07/2011] [Accepted: 06/11/2011] [Indexed: 12/20/2022] Open
Abstract
Topoisomerase 1 (Top1) enzymes regulate DNA superhelicity by forming covalent cleavage complexes that undergo controlled rotation. Substitution of nucleoside analogs at the +1 position of the DNA duplex relative to the Top1 cleavage site inhibits DNA religation. The reduced efficiency for Top1-mediated religation contributes to the anticancer activity of widely used anticancer drugs including fluoropyrimidines and gemcitabine. In the present study, we report that mismatched base pairs at the +1 position destabilize the duplex DNA components for a model Top1 cleavage complex formation even though one duplex component does not directly include a mismatched base pair. Molecular dynamics simulations reveal G-dU and G-FdU mismatched base pairs, but not a G-T mismatched base pair, increase flexibility at the Top1 cleavage site, and affect coupling between the regions required for the religation reaction to occur. These results demonstrate that substitution of dT analogs into the +1 position of the non-scissile strand alters the stability and flexibility of DNA contributing to the reduced efficiency for Top1-mediated DNA religation. These effects are inherent in the DNA duplex and do not require formation of the Top1:DNA complex. These results provide a biophysical rationale for the inhibition of Top1-mediated DNA religation by nucleotide analog substitution.
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Affiliation(s)
- William H Gmeiner
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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