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Liew D, Lim ZW, Yong EH. Machine learning-based prediction of DNA G-quadruplex folding topology with G4ShapePredictor. Sci Rep 2024; 14:24238. [PMID: 39414858 PMCID: PMC11484705 DOI: 10.1038/s41598-024-74826-2] [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: 04/24/2024] [Accepted: 09/30/2024] [Indexed: 10/18/2024] Open
Abstract
Deoxyribonucleic acid (DNA) is able to form non-canonical four-stranded helical structures with diverse folding patterns known as G-quadruplexes (G4s). G4 topologies are classified based on their relative strand orientation following the 5' to 3' phosphate backbone polarity. Broadly, G4 topologies are either parallel (4+0), antiparallel (2+2), or hybrid (3+1). G4s play crucial roles in biological processes such as DNA repair, DNA replication, transcription and have thus emerged as biological targets in drug design. While computational models have been developed to predict G4 formation, there is currently no existing model capable of predicting G4 folding topology based on its nucleic acid sequence. Therefore, we introduce G4ShapePredictor (G4SP), an application featuring a collection of multi-classification machine learning models that are trained on a custom G4 dataset combining entries from existing literature and in-house circular dichroism experiments. G4ShapePredictor is designed to accurately predict G4 folding topologies in potassium ( K + ) buffer based on its primary sequence and is able to incorporate a threshold optimization strategy allowing users to maximise precision. Furthermore, we have identified three topological sequence motifs that suggest specific G4 folding topologies of (4+0), (2+2) or (3+1) when utilising the decision-making mechanisms of G4ShapePredictor.
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Affiliation(s)
- Donn Liew
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
| | - Zi Way Lim
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
| | - Ee Hou Yong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore.
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2
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Tan C, Yan X, Lu X, Wang J, Yi X. Dual-mode colorimetric and fluorescence detection of BRCA1 based on a CRISPR-Cas12a system. Analyst 2024. [PMID: 39171896 DOI: 10.1039/d4an01035c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Breast cancer, the most common malignant tumor in the world, seriously threatens human life and health. Early diagnosis of breast cancer may help enhance the survival rate. In this work, a colorimetric and fluorescent dual-mode biosensor based on the CRISPR-Cas12a system was constructed to detect the breast cancer biomarker BRCA1. The intact G4 DNA, with the assistance of K+ and hemin, catalyses the oxidation of o-phenylenediamine (OPD) with the assistance of hydrogen peroxide (H2O2), generating the oxidation product 2,3-diaminophenazine (DAP), which has distinct absorption and fluorescence peaks. The presence of the target BRCA1 activates the trans-cleavage activity of CRISPR-Cas12a, leading to the cleavage of G4 DNA and inhibiting the catalytic oxidation of OPD. Target BRCA1 was quantitatively determined by measuring both the absorbance and fluorescence intensity of DAP. The detection limits were calculated to be 0.615 nM for the colorimetric method and 0.289 nM for the fluorescence method. The dual-mode biosensor showed good selectivity and reliability for BRCA1 and can resist interference from complex substrates, and it has great potential in biomedical detection.
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Affiliation(s)
- Chengchen Tan
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, P. R. China.
| | - Xiaolong Yan
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, P. R. China.
| | - Xingchang Lu
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, P. R. China.
| | - Jianxiu Wang
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, P. R. China.
| | - Xinyao Yi
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, P. R. China.
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3
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Wang Z, Cui R, Liu L, Li L, Li Z, Liu X, Guo Y. Nanopore-Based Single-Molecule Investigation of Cation Effect on the i-Motif Structure. J Phys Chem B 2024; 128:6830-6837. [PMID: 38959208 DOI: 10.1021/acs.jpcb.4c02021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The i-motif, a secondary structure of a four-helix formed by cytosine-rich DNA (i-DNA) through C-C+ base pairing, is prevalent in human telomeres and promoters. This structure creates steric hindrance, thereby inhibiting both gene expression and protein coding. The conformation of i-DNA is intricately linked to the intracellular ionic environment. Hence, investigating its conformation under various ion conditions holds significant importance. In this study, we explored the impact of cations on the i-motif structure at the single-molecule level using the α-hemolysin (α-HL) nanochannel. Our findings reveal that the ability of i-DNA to fold into the i-motif structure follows the order Cs+ > Na+ > K+ > Li+ for monovalent cations. Furthermore, we observed the interconversion of single-stranded DNA (ss-DNA) and the i-motif structure at high and low concentrations of Mg2+ and Ba2+ electrolyte solutions. This study not only has the potential to extend the application of i-motif-based sensors in complex solution environments but also provides a new idea for the detection of metal ions.
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Affiliation(s)
- Zhenzhao Wang
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Rikun Cui
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Lili Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Linna Li
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Zhen Li
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Xingtong Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Yanli Guo
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
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4
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Saleh EAM, Ali E, Muxamadovna GM, Kassem AF, Kaur I, Kumar A, Jabbar HS, Alwaily ER, Elawady A, Omran AA. CRISPR/Cas-based colorimetric biosensors: a promising tool for the diagnosis of bacterial foodborne pathogens in food products. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:3448-3463. [PMID: 38804827 DOI: 10.1039/d4ay00578c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Some physical phenomena and various chemical substances newly introduced in nanotechnology have allowed scientists to develop valuable devices in the field of food sciences. Regarding such progress, the identification of foodborne pathogenic microorganisms is an imperative subject nowadays. These bacterial species have been found to cause severe health impacts after food ingestion and can result in high mortality in acute cases. The rapid detection of foodborne bacterial species at low concentrations is in high demand in recent diagnostics. CRISPR/Cas-mediated biosensors possess the potential to overcome several challenges in classical assays such as complex pretreatments, long turnaround time, and insensitivity. Among them, colorimetric nanoprobes based on the CRISPR strategy afford promising devices for POCT (point-of-care testing) since they can be visualized with the naked eye and do not require diagnostic apparatus. In this study, we briefly classify and discuss the working principles of the different CRISPR/Cas protein agents that have been employed in biosensors so far. We assess the current status of the CRISPR system, specifically focusing on colorimetric biosensing platforms. We discuss the utilization of each Cas effector in the detection of foodborne pathogens and examine the restrictions of the existing technology. The challenges and future opportunities are also indicated and addressed.
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Affiliation(s)
- Ebraheem Abdu Musad Saleh
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, 11942, Saudi Arabia.
| | - Eyhab Ali
- Al-Zahraa University for Women, Karbala, Iraq
| | | | - Asmaa F Kassem
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, 11942, Saudi Arabia
- Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Irwanjot Kaur
- Department of Biotechnology and Genetics, Jain (Deemed-to-be) University, Bengaluru, Karnataka-560069, India
- Department of Allied Healthcare and Sciences, Vivekananda Global University, Jaipur, Rajasthan-303012, India
| | - Abhinav Kumar
- Department of Nuclear and Renewable Energy, Ural Federal University Named After the First President of Russia Boris Yeltsin, Yekaterinburg 620002, Russia
| | - Hijran Sanaan Jabbar
- Department of Chemistry, College of Science, Salahaddin University-Erbil, Erbil, Kurdistan Region, Iraq
| | - Enas R Alwaily
- Microbiology Research Group, College of Pharmacy, Al-Ayen University, Thi-Qar, Iraq
| | - Ahmed Elawady
- College of Technical Engineering, The Islamic University of Al Diwaniyah, Al Diwaniyah, Iraq
- College of Technical Engineering, The Islamic University, Najaf, Iraq
- College of Technical Engineering, The Islamic University of Babylon, Babylon, Iraq
| | - Alaa A Omran
- Department of Engineering, AL-Nisour University College, Baghdad, Iraq
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5
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Takiguchi S, Kambara F, Tani M, Sugiura T, Kawano R. Simultaneous Recognition of Over- and Under-Expressed MicroRNAs Using Nanopore Decoding. Anal Chem 2023; 95:14675-14685. [PMID: 37675494 PMCID: PMC10797591 DOI: 10.1021/acs.analchem.3c02560] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/28/2023] [Indexed: 09/08/2023]
Abstract
This paper describes a strategy for simultaneous recognition of over- and under-expressed microRNAs (miRNAs) using the method of signal classification-based nanopore decoding. MiRNA has attracted attention as a promising biomarker for cancer diagnosis owing to its cancer-type-specific expression patterns. While nanopore technology has emerged as a simple and label-free method to detect miRNAs and their expression patterns, recognizing patterns involving simultaneous over/under-expression is still challenging due to the inherent working principles. Here, inspired by the sequence design for DNA computation with nanopore decoding, we designed diagnostic DNA probes targeting two individual over/under-expressed miRNAs in the serum of oral squamous cell carcinoma. Through nanopore measurements, our designed probes exhibited characteristic current signals depending on the hybridized miRNA species, which were plotted on the scatter plot of duration versus current blocking ratio. The classified signals reflected the relative abundance of target miRNAs, thereby enabling successful pattern recognition of over/under-expressed miRNAs, even when using clinical samples. We believe that our method paves the way for miRNA-targeting simple diagnosis as a liquid biopsy.
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Affiliation(s)
- Sotaro Takiguchi
- Department
of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Fumika Kambara
- Department
of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Mika Tani
- Department
of Maxillofacial Diagnostic and Surgical Science, Field of Oral and
Maxillofacial Rehabilitation, Graduate School of Medical and Dental
Science, Kagoshima University, Kagoshima 890-8544, Japan
| | - Tsuyoshi Sugiura
- Department
of Maxillofacial Diagnostic and Surgical Science, Field of Oral and
Maxillofacial Rehabilitation, Graduate School of Medical and Dental
Science, Kagoshima University, Kagoshima 890-8544, Japan
- Division
of Oral and Maxillofacial Oncology and Surgical Sciences, Graduate
School of Dentistry, Tohoku University, Miyagi 980-8577, Japan
| | - Ryuji Kawano
- Department
of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
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6
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Chingarande RG, Tian K, Kuang Y, Sarangee A, Hou C, Ma E, Ren J, Hawkins S, Kim J, Adelstein R, Chen S, Gillis KD, Gu LQ. Real-time label-free detection of dynamic aptamer-small molecule interactions using a nanopore nucleic acid conformational sensor. Proc Natl Acad Sci U S A 2023; 120:e2108118120. [PMID: 37276386 PMCID: PMC10268594 DOI: 10.1073/pnas.2108118120] [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: 05/18/2021] [Accepted: 04/14/2023] [Indexed: 06/07/2023] Open
Abstract
Nucleic acids can undergo conformational changes upon binding small molecules. These conformational changes can be exploited to develop new therapeutic strategies through control of gene expression or triggering of cellular responses and can also be used to develop sensors for small molecules such as neurotransmitters. Many analytical approaches can detect dynamic conformational change of nucleic acids, but they need labeling, are expensive, and have limited time resolution. The nanopore approach can provide a conformational snapshot for each nucleic acid molecule detected, but has not been reported to detect dynamic nucleic acid conformational change in response to small -molecule binding. Here we demonstrate a modular, label-free, nucleic acid-docked nanopore capable of revealing time-resolved, small molecule-induced, single nucleic acid molecule conformational transitions with millisecond resolution. By using the dopamine-, serotonin-, and theophylline-binding aptamers as testbeds, we found that these nucleic acids scaffolds can be noncovalently docked inside the MspA protein pore by a cluster of site-specific charged residues. This docking mechanism enables the ion current through the pore to characteristically vary as the aptamer undergoes conformational changes, resulting in a sequence of current fluctuations that report binding and release of single ligand molecules from the aptamer. This nanopore tool can quantify specific ligands such as neurotransmitters, elucidate nucleic acid-ligand interactions, and pinpoint the nucleic acid motifs for ligand binding, showing the potential for small molecule biosensing, drug discovery assayed via RNA and DNA conformational changes, and the design of artificial riboswitch effectors in synthetic biology.
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Affiliation(s)
- Rugare G. Chingarande
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO65211
| | - Kai Tian
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO65211
| | - Yu Kuang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO65211
| | - Aby Sarangee
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Chengrui Hou
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Emily Ma
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Jarett Ren
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Sam Hawkins
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Joshua Kim
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Ray Adelstein
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Sally Chen
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
| | - Kevin D. Gillis
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO65211
| | - Li-Qun Gu
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, MO65211
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO65211
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7
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Kohlberger M, Gadermaier G. SELEX: Critical factors and optimization strategies for successful aptamer selection. Biotechnol Appl Biochem 2022; 69:1771-1792. [PMID: 34427974 PMCID: PMC9788027 DOI: 10.1002/bab.2244] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/22/2021] [Indexed: 12/30/2022]
Abstract
Within the last decade, the application range of aptamers in biochemistry and medicine has expanded rapidly. More than just a replacement for antibodies, these intrinsically structured RNA- or DNA-oligonucleotides show great potential for utilization in diagnostics, specific drug delivery, and treatment of certain medical conditions. However, what is analyzed less frequently is the process of aptamer identification known as systematic evolution of ligands by exponential enrichment (SELEX) and the functional mechanisms that lie at its core. SELEX involves numerous singular processes, each of which contributes to the success or failure of aptamer generation. In this review, critical steps during aptamer selection are discussed in-depth, and specific problems are presented along with potential solutions. The discussed aspects include the size and molecule type of the selected target, the nature and stringency of the selection process, the amplification step with its possible PCR bias, the efficient regeneration of RNA or single-stranded DNA, and the different sequencing procedures and screening assays currently available. Finally, useful quality control steps and their role within SELEX are presented. By understanding the mechanisms through which aptamer selection is influenced, the design of more efficient SELEX procedures leading to a higher success rate in aptamer identification is enabled.
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Affiliation(s)
- Michael Kohlberger
- Department of BiosciencesParis Lodron University SalzburgSalzburgAustria,Christian Doppler Laboratory for Biosimilar CharacterizationParis Lodron University SalzburgSalzburgAustria
| | - Gabriele Gadermaier
- Department of BiosciencesParis Lodron University SalzburgSalzburgAustria,Christian Doppler Laboratory for Biosimilar CharacterizationParis Lodron University SalzburgSalzburgAustria
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8
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Sensitive Detection of Staphylococcus aureus by a Colorimetric Biosensor Based on Magnetic Separation and Rolling Circle Amplification. Foods 2022; 11:foods11131852. [PMID: 35804667 PMCID: PMC9265873 DOI: 10.3390/foods11131852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 02/05/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a common foodborne pathogen that causes fever, vomiting, and other intestinal symptoms, and seriously affects human health and social safety. As a result, a reliable and sensitive detection technique for S. aureus must be developed. In this work, we proposed a sandwich assay on vancomycin functionalized magnetic beads (Van-MNPs) for S. aureus detection based on the specific binding between IgG and targets. The Van-MNPs were used as a tool for the separation of target bacteria. The biotin-modified IgG mediates binding between DNA nanoflowers (DNFs) and the target bacteria via interacting with streptavidin. The DNFs prepared by rolling circle amplification (RCA) were employed as a nano-container to enhance the capacity of biotins, and the streptavidin-horseradish peroxidase (SA-HRP) was loaded onto DNFs to catalyze the color change of TMB. Therefore, a colorimetric biosensor based on magnetic separation and rolling circle amplification was developed. The proposed methods for S. aureus detection showed a limit of detection (LOD) of 3.3 × 103 CFU/mL and excellent specificity. The biosensor has a certain reference value for the detection of S. aureus in juice.
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9
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Zhu J, Bošković F, Keyser UF. Split G-Quadruplexes Enhance Nanopore Signals for Simultaneous Identification of Multiple Nucleic Acids. NANO LETTERS 2022; 22:4993-4998. [PMID: 35730196 PMCID: PMC9228402 DOI: 10.1021/acs.nanolett.2c01764] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 05/28/2022] [Indexed: 05/22/2023]
Abstract
Assembly of DNA structures based on hybridization like split G-quadruplex (GQ) have great potential for the base-pair specific identification of nucleic acid targets. Herein, we combine multiple split G-quadruplex (GQ) assemblies on designed DNA nanostructures (carrier) with a solid-state nanopore sensing platform. The split GQ probes recognize various nucleic acid sequences in a parallel assay that is based on glass nanopore analysis of molecular structures. Specifically, we split a GQ into two asymmetric parts extended with sequences complementary to the target. The longer G-segment is in solution, and the shorter one is on a DNA carrier. If the target is present, the two separate GQ parts will be brought together to facilitate the split GQ formation and enhance the nanopore signal. We demonstrated detection of multiple target sequences from different viruses with low crosstalk. Given the programmability of this DNA based nanopore sensing platform, it is promising in biosensing.
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10
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An aptamer-assisted biological nanopore biosensor for ultra-sensitive detection of ochratoxin A with a portable single-molecule measuring instrument. Talanta 2022; 248:123619. [PMID: 35671547 DOI: 10.1016/j.talanta.2022.123619] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/06/2022] [Accepted: 05/25/2022] [Indexed: 11/22/2022]
Abstract
Biological nanopore-based single-molecule detection technology has shown ultrahigh sensitivity to various target analyte. But the detection scope of interesting targets is limited due to the lack of effective signal conversion strategies. In addition, conventional nanopore detection instruments are cumbersome, resulting nanopore detection can only be performed in laboratory. Herein, a customizable nanopore current amplifier is constructed to lower the cost and increase the portability of the nanopore instrument, and then an immobilized aptamer-based signal conversion strategy is proposed for α-hemolysin (α-HL) nanopore to detect small molecules (ochratoxin A, OTA). The presence of OTA in sample would trigger the release of probe single-strand DNA (ssDNA) from magnetic beads, which could subsequently cause current blockage in nanopore. The results show that the signal frequency of probe ssDNA has a linear relationship with the OTA concentration in the range of 2 × 101~2 × 103 pmol/L. Compared to other methods, our sensing system has achieved an ultra-sensitive detection of OTA with the detection limit as low as 1.697 pmol/L. This strategy could broaden the scope of nanopore detection and have the potential for rapid and in-situ detection of other food contaminants in the future.
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11
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Li F, Luo Y, Xi G, Fu J, Tu J. Single-Molecule Analysis of DNA structures using nanopore sensors. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2022. [DOI: 10.1016/j.cjac.2022.100089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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12
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Green AT, Pickard AJ, Li R, MacKerell AD, Bierbach U, Cho SS. Computational and Experimental Characterization of rDNA and rRNA G-Quadruplexes. J Phys Chem B 2022; 126:609-619. [PMID: 35026949 DOI: 10.1021/acs.jpcb.1c08340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA G-quadruplexes in human telomeres and gene promoters are being extensively studied for their role in controlling the growth of cancer cells. G-quadruplexes have been unambiguously shown to exist both in vitro and in vivo, including in the guanine (G)-rich DNA genes encoding pre-ribosomal RNA (pre-rRNA), which is transcribed in the cell's nucleolus. Recent studies strongly suggest that these DNA sequences ("rDNA"), and the transcribed rRNA, are a potential anticancer target through the inhibition of RNA polymerase I (Pol I) in ribosome biogenesis, but the structures of ribosomal G-quadruplexes at atomic resolution are unknown and very little biophysical characterization has been performed on them to date. In the present study, circular dichroism (CD) spectroscopy is used to show that two putative rDNA G-quadruplex sequences, NUC 19P and NUC 23P and their counterpart rRNAs, predominantly adopt parallel topologies, reminiscent of the analogous telomeric quadruplex structures. Based on this information, we modeled parallel topology atomistic structures of the putative ribosomal G-quadruplexes. We then validated and refined the modeled ribosomal G-quadruplex structures using all-atom molecular dynamics (MD) simulations with the CHARMM36 force field in the presence and absence of stabilizing K+. Motivated by preliminary MD simulations of the telomeric parallel G-quadruplex (TEL 24P) in which the K+ ion is expelled, we used updated CHARMM36 force field K+ parameters that were optimized, targeting the data from quantum mechanical calculations and the polarizable Drude model force field. In subsequent MD simulations with optimized CHARMM36 parameters, the K+ ions are predominantly in the G-quadruplex channel and the rDNA G-quadruplexes have more well-defined, predominantly parallel-topology structures as compared to rRNA. In addition, NUC 19P is more structured than NUC 23P, which contains extended loops. Results from this study set the structural foundation for understanding G-quadruplex functions and the design of novel chemotherapeutics against these nucleolar targets and can be readily extended to other DNA and RNA G-quadruplexes.
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Affiliation(s)
- Adam T Green
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Amanda J Pickard
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Rongzhong Li
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
| | - Ulrich Bierbach
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Samuel S Cho
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
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13
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Bialy RM, Li Y, Brennan JD. Target-Dependent Protection of DNA Aptamers against Nucleolytic Digestion Enables Signal-On Biosensing with Toehold-Mediated Rolling Circle Amplification. Chemistry 2021; 27:14543-14549. [PMID: 34437748 DOI: 10.1002/chem.202102975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Indexed: 02/06/2023]
Abstract
We report a generalizable strategy for biosensing that takes advantage of the resistance of DNA aptamers against nuclease digestion when bound with their targets, coupled with toehold mediated strand displacement (TMSD) and rolling circle amplification (RCA). A DNA aptamer containing a toehold extension at its 5'-end protects it from 3'-exonuclease digestion by phi29 DNA polymerase (phi29 DP) in a concentration-dependent manner. The protected aptamer can participate in RCA in the presence of a circular template that is designed to free the aptamer from its target via TMSD. The absence of the target leads to aptamer digestion, and thus no RCA product is produced, resulting in a turn-on sensor. Using two different DNA aptamers, we demonstrate rapid and quantitative real-time fluorescence detection of two human proteins: platelet-derived growth factor (PDGF) and thrombin. Sensitive detection of PDGF was also achieved in human serum and human plasma, demonstrating the selectivity of the assay.
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Affiliation(s)
- Roger M Bialy
- Biointerfaces Institute, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4O3, Canada
| | - Yingfu Li
- Biointerfaces Institute, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4O3, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1, Canada
| | - John D Brennan
- Biointerfaces Institute, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4O3, Canada
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14
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Pal S, Paul S. Theoretical investigation of conformational deviation of the human parallel telomeric G-quadruplex DNA in the presence of different salt concentrations and temperatures under confinement. Phys Chem Chem Phys 2021; 23:14372-14382. [PMID: 34179908 DOI: 10.1039/d0cp06702d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Various experimental reports address the stability of G-quadruplex DNA inside a close confinement such as α-hemolysin, nanocavity water pool and different metal-organic-frameworks (MOFs). To understand the conformational change of G-quadruplex DNA at the atomistic level, we have carried out a total of 40 μs simulation run under both non-polar and polar confinement conditions. To investigate the dynamics, we have considered two different KCl salt concentrations, i.e., 0.47 M (minimal salt concentration) and higher than 2 M (higher salt concentration), at two distinct temperatures, 300 K and 350 K. Here, we have observed that the human telomeric G-quadruplex DNA deviates more from its crystal structure at minimal salt concentration under both non-polar and polar confinement conditions. Besides, the loop regions deviate and fluctuate more compared to the other regions, i.e., sugar-phosphate backbone and tetrad regions. The presence of K+ ions is found to be primarily responsible for this phenomenon. From the spatial density function (SDF) plots, a higher density of K+ ions is observed in the backbone region. Furthermore, from the residue-wise first solvation shell estimation, we have noticed that the K+ ions mainly accumulate in the tetrad region under both non-polar and polar confinement conditions due to which the tetrad regions are more rigid than the loop regions. Higher salt concentration results in increased rigidity of the G-quadruplex DNA. Our study provides valuable insight into the conformational deviation of the G-quadruplex DNA under nanoconfinement conditions.
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Affiliation(s)
- Saikat Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam-781039, India.
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam-781039, India.
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15
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Xi D, Cui M, Zhou X, Zhuge X, Ge Y, Wang Y, Zhang S. Nanopore-Based Single-Molecule Investigation of DNA Sequences with Potential to Form i-Motif Structures. ACS Sens 2021; 6:2691-2699. [PMID: 34237940 DOI: 10.1021/acssensors.1c00712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
i-Motifs are DNA secondary structures present in cytosine-rich sequences. These structures are formed in regulatory regions of the human genome and play key regulatory roles. The investigation of sequences capable of forming i-motif structures at the single-molecule level is highly important. In this study, we used α-hemolysin nanopores to systematically study a series of DNA sequences at the nanometer scale by providing structure-dependent signature current signals to gain in-sights into the i-motif DNA sequence and structural stability. Increasing the length of the cytosine tract in a range of 3-10 nucleobases resulted in a longer translocation time through the pore, indicating improved stability. Changing the loop sequence and length in the sequences did not affect the formation of the i-motif structure but changed its stability. Importantly, the application of all-atom molecular dynamics simulations revealed the structural morphology of all sequences. Based on these results, we postulated a folding rule for i-motif formation, suggesting that thousands of cytosine-rich sequences in the human genome might fold into i-motif structures. Many of these were found in locations where structure formation is likely to play regulatory roles. These findings provide insights into the application of nanopores as a powerful tool for discovering potential i-motif-forming sequences and lay a foundation for future studies exploring the biological roles of i-motifs.
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Affiliation(s)
- Dongmei Xi
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Life Sciences, Linyi University, Linyi 276005, P. R. China
| | - Mengjie Cui
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
| | - Xin Zhou
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
| | - Xiao Zhuge
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
| | - Yaxian Ge
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
| | - Ying Wang
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Life Sciences, Linyi University, Linyi 276005, P. R. China
| | - Shusheng Zhang
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
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16
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Luchian T, Mereuta L, Park Y, Asandei A, Schiopu I. Single-molecule, hybridization-based strategies for short nucleic acids detection and recognition with nanopores. Proteomics 2021; 22:e2100046. [PMID: 34275186 DOI: 10.1002/pmic.202100046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/21/2021] [Accepted: 07/13/2021] [Indexed: 12/23/2022]
Abstract
DNA nanotechnology has seen large developments over the last 30 years through the combination of detection and discovery of DNAs, and solid phase synthesis to increase the chemical functionalities on nucleic acids, leading to the emergence of novel and sophisticated in features, nucleic acids-based biopolymers. Arguably, nanopores developed for fast and direct detection of a large variety of molecules, are part of a revolutionary technological evolution which led to cheaper, smaller and considerably easier to use devices enabling DNA detection and sequencing at the single-molecule level. Through their versatility, the nanopore-based tools proved useful biomedicine, nanoscale chemistry, biology and physics, as well as other disciplines spanning materials science to ecology and anthropology. This mini-review discusses the progress of nanopore- and hybridization-based DNA detection, and explores a range of state-of-the-art applications afforded through the combination of certain synthetically-derived polymers mimicking nucleic acids and nanopores, for the single-molecule biophysics on short DNA structures.
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Affiliation(s)
- Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Alina Asandei
- Interdisciplinary Research Institute, Sciences Department, "Alexandru I. Cuza" University, Iasi, Romania
| | - Irina Schiopu
- Interdisciplinary Research Institute, Sciences Department, "Alexandru I. Cuza" University, Iasi, Romania
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17
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Frutiger A, Tanno A, Hwu S, Tiefenauer RF, Vörös J, Nakatsuka N. Nonspecific Binding-Fundamental Concepts and Consequences for Biosensing Applications. Chem Rev 2021; 121:8095-8160. [PMID: 34105942 DOI: 10.1021/acs.chemrev.1c00044] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Nature achieves differentiation of specific and nonspecific binding in molecular interactions through precise control of biomolecules in space and time. Artificial systems such as biosensors that rely on distinguishing specific molecular binding events in a sea of nonspecific interactions have struggled to overcome this issue. Despite the numerous technological advancements in biosensor technologies, nonspecific binding has remained a critical bottleneck due to the lack of a fundamental understanding of the phenomenon. To date, the identity, cause, and influence of nonspecific binding remain topics of debate within the scientific community. In this review, we discuss the evolution of the concept of nonspecific binding over the past five decades based upon the thermodynamic, intermolecular, and structural perspectives to provide classification frameworks for biomolecular interactions. Further, we introduce various theoretical models that predict the expected behavior of biosensors in physiologically relevant environments to calculate the theoretical detection limit and to optimize sensor performance. We conclude by discussing existing practical approaches to tackle the nonspecific binding challenge in vitro for biosensing platforms and how we can both address and harness nonspecific interactions for in vivo systems.
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Affiliation(s)
- Andreas Frutiger
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
| | - Alexander Tanno
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
| | - Stephanie Hwu
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
| | - Raphael F Tiefenauer
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
| | - János Vörös
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
| | - Nako Nakatsuka
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich CH-8092, Switzerland
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18
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Vafaei S, Allabush F, Tabaei SR, Male L, Dafforn TR, Tucker JHR, Mendes PM. Förster Resonance Energy Transfer Nanoplatform Based on Recognition-Induced Fusion/Fission of DNA Mixed Micelles for Nucleic Acid Sensing. ACS NANO 2021; 15:8517-8524. [PMID: 33961404 PMCID: PMC8158853 DOI: 10.1021/acsnano.1c00156] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/29/2021] [Indexed: 05/29/2023]
Abstract
The dynamic nature of micellar nanostructures is employed to form a self-assembled Förster resonance energy transfer (FRET) nanoplatform for enhanced sensing of DNA. The platform consists of lipid oligonucleotide FRET probes incorporated into micellar scaffolds, where single recognition events result in fusion and fission of DNA mixed micelles, triggering the fluorescence response of multiple rather than a single FRET pair. In comparison to conventional FRET substrates where a single donor interacts with a single acceptor, the micellar multiplex FRET system showed ∼20- and ∼3-fold enhancements in the limit of detection and FRET efficiency, respectively. This supramolecular signal amplification approach could potentially be used to improve FRET-based diagnostic assays of nucleic acid and non-DNA based targets.
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Affiliation(s)
- Setareh Vafaei
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Francia Allabush
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Seyed R. Tabaei
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Louise Male
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Timothy R. Dafforn
- School
of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - James H. R. Tucker
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Paula M. Mendes
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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19
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Gong YP, Yang J, Fang JW, Li Q, Yu ZY, Guan A, Gong HY. A DNA small molecular probe with increasing K + concentration promoted selectivity. RSC Adv 2021; 11:15030-15035. [PMID: 35424063 PMCID: PMC8697834 DOI: 10.1039/d0ra06274j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 03/28/2021] [Indexed: 11/21/2022] Open
Abstract
DNA small molecular probe study was considered as a promising approach to achieve DNA related disease diagnosis. Most related reports were performed under specific salinity. Herein, 4-imino-3-(pyridin-2-yl)-4H-quinolizine-1-carbonitrile (IPQC) was generated via a facile procedure with high yield (85%). It is found that IPQC could act as a universal probe for most tested ssDNA, dsDNA and G4 DNA in low [K+] concentration (less than 20 mM). However, IPQC showed highly selective G4 DNA binding via UV-vis and fluorescence response in increasing [K+] (e.g., 150 mM) conditions. The ion atmosphere effects are instructive for DNA probe exploration. This provides guidance for the design, selection and optimization of the probes for target DNA sensing.
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Affiliation(s)
- Ya-Ping Gong
- Department of Chemistry, Renmin University of China Beijing 100872 P. R. China
- Institute of Chemistry, Chinese Academy of Sciences Zhongguancunbeiyijie 2 Beijing 100190 P. R. China
| | - Jian Yang
- College of Chemistry, Beijing Normal University Xinjiekouwaidajie 19 Beijing 100875 P. R. China
| | - Ji-Wang Fang
- Department of Chemistry, Renmin University of China Beijing 100872 P. R. China
- College of Chemistry, Beijing Normal University Xinjiekouwaidajie 19 Beijing 100875 P. R. China
| | - Qian Li
- Institute of Chemistry, Chinese Academy of Sciences Zhongguancunbeiyijie 2 Beijing 100190 P. R. China
| | - Zhi-Yong Yu
- Department of Chemistry, Renmin University of China Beijing 100872 P. R. China
| | - Aijiao Guan
- Institute of Chemistry, Chinese Academy of Sciences Zhongguancunbeiyijie 2 Beijing 100190 P. R. China
| | - Han-Yuan Gong
- College of Chemistry, Beijing Normal University Xinjiekouwaidajie 19 Beijing 100875 P. R. China
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20
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Alieva R, Novikov R, Tashlitsky V, Arutyunyan A, Kopylov A, Zavyalova E. Bimodular thrombin aptamers with two types of non-covalent locks. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2021; 40:559-577. [PMID: 33847237 DOI: 10.1080/15257770.2021.1910297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023]
Abstract
Aptamers are structured oligonucleotides that specifically bind their targets. Oligonucleotides can be assembled in large nanostructures via intermolecular duplexes or G-quadruplexes. Addition of aptamers can be used to create nanostructures that bind specifically certain targets. Here two types of self-assembling locks were used to create bimodular aptamer constructions. Well-known aptamer to thrombin was chosen as a model object. The assembly of duplex locks was more efficient at low concentrations. The functional activity of aptamer modules was nearly the same as in HD1. However, the affinity of bimodular aptamers with G-quadruplex locks to immobilized thrombin was 5-10 times higher.
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Affiliation(s)
- Rugiya Alieva
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Roman Novikov
- Engelhardt Institute of Molecular Biology RAS, Moscow, Russian Federation
| | - Vadim Tashlitsky
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Alexander Arutyunyan
- Belozersky Research Institute of Physical Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Alexey Kopylov
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Elena Zavyalova
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russian Federation
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21
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Tang J, Wu J, Zhu R, Wang Z, Zhao C, Tang P, Xie W, Wang D, Liang L. Reversible photo-regulation on the folding/unfolding of telomere G-quadruplexes with solid-state nanopores. Analyst 2021; 146:655-663. [PMID: 33206065 DOI: 10.1039/d0an01930e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The formation of G-quadruplexes (G4) in human telomere and other important biological regions inhibits the replication and transcription of DNA, thereby influencing further cell proliferation. The investigation of G4 formation and unfolding is vital for understanding their modulation in biological processes and life science. Photo regulation is a facile and sensitive approach for monitoring the structures of biomacromolecules and material surface properties. The nanopore-based technique is also prevalent for label-free single-molecule characterization with high accuracy. This study provides a combination of solid-state nanopore technology with light-switch as a platform for the modulation of human telomere G4 formation and splitting under switchable light exposure. The introduction of molecular switch, namely azobenzene moiety at different positions of the DNA sequence influences the formation and stability of G4. Three azobenzenes immobilized on each of the G-quartet plane (hTelo-3azo-p) or four azobenzenes on the same plane (hTelo-4azo-4p) of the human telomere G4 sequence realized the reversible control of G4 folding/unfolding at the temporal scale upon photo regulation, and the formation and splitting of G4 with hTelo-4azo-4p is slower and not thorough compared to that with hTelo-3azo-p due to the coplanar steric hindrance. Moreover, the G4 formation recorded with the combined nanopore and photo-responsive approach was also characterized with fluorescence, and the variation in the fluorescence intensity of the NMM and G4 complex exhibited a different tendency under reverse light irradiation due to the distinct interactions of NMM with the azobenzene-modified G4. Our study demonstrated a controllable and sensitive way for the manipulation of G4 structures, which will be inspiring for the intervention of G4-related cell senescence, cancer diagnosis and drug exploration.
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Affiliation(s)
- Jing Tang
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, P. R. China.
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22
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Crnković A, Srnko M, Anderluh G. Biological Nanopores: Engineering on Demand. Life (Basel) 2021; 11:life11010027. [PMID: 33466427 PMCID: PMC7824896 DOI: 10.3390/life11010027] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/24/2020] [Accepted: 12/31/2020] [Indexed: 12/17/2022] Open
Abstract
Nanopore-based sensing is a powerful technique for the detection of diverse organic and inorganic molecules, long-read sequencing of nucleic acids, and single-molecule analyses of enzymatic reactions. Selected from natural sources, protein-based nanopores enable rapid, label-free detection of analytes. Furthermore, these proteins are easy to produce, form pores with defined sizes, and can be easily manipulated with standard molecular biology techniques. The range of possible analytes can be extended by using externally added adapter molecules. Here, we provide an overview of current nanopore applications with a focus on engineering strategies and solutions.
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23
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Reynaud L, Bouchet-Spinelli A, Raillon C, Buhot A. Sensing with Nanopores and Aptamers: A Way Forward. SENSORS 2020; 20:s20164495. [PMID: 32796729 PMCID: PMC7472324 DOI: 10.3390/s20164495] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 12/13/2022]
Abstract
In the 90s, the development of a novel single molecule technique based on nanopore sensing emerged. Preliminary improvements were based on the molecular or biological engineering of protein nanopores along with the use of nanotechnologies developed in the context of microelectronics. Since the last decade, the convergence between those two worlds has allowed for biomimetic approaches. In this respect, the combination of nanopores with aptamers, single-stranded oligonucleotides specifically selected towards molecular or cellular targets from an in vitro method, gained a lot of interest with potential applications for the single molecule detection and recognition in various domains like health, environment or security. The recent developments performed by combining nanopores and aptamers are highlighted in this review and some perspectives are drawn.
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24
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Ji N, Shi HQ, Fang XY, Wu ZY. Exploring the interaction of G-quadruplex and porphyrin derivative by single protein nanopore sensing interface. Anal Chim Acta 2020; 1106:126-132. [DOI: 10.1016/j.aca.2020.01.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/18/2020] [Accepted: 01/23/2020] [Indexed: 11/26/2022]
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25
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Liu J, Feng W, Zhang W. A single-molecule study reveals novel rod-like structures formed by a thrombin aptamer repeat sequence. NANOSCALE 2020; 12:4159-4166. [PMID: 32022812 DOI: 10.1039/c9nr09054a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thrombin aptamers (TBAs) have attracted much attention due to their various applications. The structures and properties of long ssDNA chains with multiple TBA repeat sequences are interesting and distinct from those of their monomers. Due to the complexity of the sample system, it is quite difficult to reveal the structure of such a long-chain ssDNA using traditional methods. In this work, we investigated the repeated ssDNA by using single-molecule magnetic tweezers and AFM imaging. To do that we developed the polymerase change-rolling circle amplification (PC-RCA) synthetic method and prepared two-end modified repeated ssDNA. The rod-like G4 structures formed by intramolecular stacking of the repeat sequence were for the first time identified. This novel structure is different from those higher-order quadruplex structures formed by G-tetrads or loop-mediated interactions. It is also quite interesting to find that the increase of the TBA copy number can unitize the diversity of TBA conformation to the best-fit binding structure for thrombin. The methodology developed in this work can be used for studying other repeat sequences in the genome, such as telomeric DNA as well as interactions of ssDNA with the binding molecule.
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Affiliation(s)
- Jianyu Liu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
| | - Wei Feng
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wenke Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
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26
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Xuan TF, Liu J, Wang ZQ, Chen WM, Lin J. Fluorescent Detection of the Ubiquitous Bacterial Messenger 3',5' Cyclic Diguanylic Acid by Using a Small Aromatic Molecule. Front Microbiol 2020; 10:3163. [PMID: 31993044 PMCID: PMC6970945 DOI: 10.3389/fmicb.2019.03163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/31/2019] [Indexed: 12/28/2022] Open
Abstract
3′,5′ Cyclic diguanylic acid (c-di-GMP) has been shown to play a central role in the regulation of bacterial physiological processes such as biofilm formation and virulence production, and is regarded as a potential target for the development of anti-infective drugs. A method for the facile detection of the bacterial level of cellular c-di-GMP is required to explore the details of c-di-GMP signaling and design drugs on the basis of this pathway. Current methods of c-di-GMP detection have limited sensitivity or difficultly in probe preparation. Herein a new fluorescent probe is reported for the detection of c-di-GMP at concentrations as low as 500 nM. The probe was developed on the basis of the G-quadruplex formation of c-di-GMP induced by aromatic molecules. When used on crude bacterial cell lysates, it can effectively distinguish between the low c-di-GMP levels of bacteria in plankton and the high c-di-GMP levels in biofilm. The method described here is simple, inexpensive, sensitive, and suitable for practical applications involving the rapid detection of cellular c-di-GMP levels in vitro after simple bacterial lysis and filtration.
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Affiliation(s)
- Teng-Fei Xuan
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China
| | - Jun Liu
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China
| | - Zi-Qiang Wang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China
| | - Wei-Min Chen
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China
| | - Jing Lin
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China
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27
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Gonnelli A, Pieraccini S, Baldassarri EJ, Funari S, Masiero S, Ortore MG, Mariani P. Metallo-responsive self-assembly of lipophilic guanines in hydrocarbon solvents: a systematic SAXS structural characterization. NANOSCALE 2020; 12:1022-1031. [PMID: 31845695 DOI: 10.1039/c9nr08556d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Lipophilic guanines (LipoGs) in aprotic solvents undergo different self-assembly processes based on different H-bonded motifs. Cylindrical nanotubes made by π-π stacked guanine tetramers (G-quadruplexes) and flat, tape-like aggregates (G-ribbons) have been observed depending on the presence of alkali metal ions. To obtain information on the structural properties and stability of these LipoG aggregates, Small-Angle X-ray Scattering (SAXS) experiments have been performed in dodecane, both in the presence and in the absence of potassium ions. As a result, the occurrence of the two different metallo-responsive architectures (nanoribbons or columnar nanotubes) was confirmed and we reported here for the first time a systematic study on the dependence of the aggregate properties on composition, temperature and molecular unit structure. Even if dodecane was selected to favour LipoG solubility, a strong tendency to self-organize into ordered lyotropic phases was indeed detected.
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Affiliation(s)
- Adriano Gonnelli
- Dipartimento di Scienze della Vita e dell'Ambiente, Biophysics Research Group, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
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28
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Wang S, Liang L, Tang J, Cai Y, Zhao C, Fang S, Wang H, Weng T, Wang L, Wang D. Label-free single-molecule identification of telomere G-quadruplexes with a solid-state nanopore sensor. RSC Adv 2020; 10:27215-27224. [PMID: 35515777 PMCID: PMC9055465 DOI: 10.1039/d0ra05083k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Telomere sequences can spontaneously form G-quadruplexes (G4) in the presence of some cations. In view of their relevance to genetic processes and potential as therapeutic-targets, hitherto, a wealth of conventional techniques have been reported for interrogation of G4 conformation diversity and corresponding folding kinetics, most of which are limited in precision and sensitivity. This work introduces a label-free solid-state nanopore (SSN) approach for the determination of inter-, intra- and tandem molecular G4 with distinct base permutation in various cation buffers with a tailored aperture and meanwhile captures the single-molecule G4 folding process. SSN translocation properties elucidated that both inter- and intramolecular G4 generated higher current blockage with longer duration than flexible homopolymer nucleotide, and intramolecular G4 are structurally more stable with higher event frequency and longer blockage time than intermolecular ones; base arrangement played weak role in translocation behaviors; the same sequences with one, two and three G4 skeletons displayed an increase in current blockage and a gradual extension in dwell time with the increase of molecule size recorded in the same nanopore. We observed the conformation change of single-molecule G4 which indicated the existence of folding/unfolding equilibration in nanopore, and real-time test suggested a gradual formation of G4 with time. Our results could provide a continued and improved understanding of the underlying relevance of structural stability and G4 folding process by utilizing SSN platform which exhibits strategic potential advances over the other methods with high spatial and temporal resolution. Nanopore detection of single-molecule G-quadruplexes.![]()
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A DNA-Based Biosensor Assay for the Kinetic Characterization of Ion-Dependent Aptamer Folding and Protein Binding. Molecules 2019; 24:molecules24162877. [PMID: 31398834 PMCID: PMC6718989 DOI: 10.3390/molecules24162877] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 11/16/2022] Open
Abstract
Therapeutic and diagnostic nucleic acid aptamers are designed to bind tightly and specifically to their target. The combination of structural and kinetic analyses of aptamer interactions has gained increasing importance. Here, we present a fluorescence-based switchSENSE aptasensor for the detailed kinetic characterization of aptamer-analyte interaction and aptamer folding, employing the thrombin-binding aptamer (TBA) as a model system. Thrombin-binding aptamer folding into a G-quadruplex and its binding to thrombin strongly depend on the type and concentration of ions present in solution. We observed conformational changes induced by cations in real-time and determined the folding and unfolding kinetics of the aptamer. The aptamer's affinity for K+ was found to be more than one order of magnitude higher than for other cations (K+ > NH4+ >> Na+ > Li+). The aptamer's affinity to its protein target thrombin in the presence of different cations followed the same trend but differed by more than three orders of magnitude (KD = 0.15 nM to 250 nM). While the stability (kOFF) of the thrombin-TBA complex was similar in all conditions, the cation type strongly influenced the association rate (kON). These results demonstrated that protein-aptamer binding is intrinsically related to the correct aptamer fold and, hence, to the presence of stabilizing ions. Because fast binding kinetics with on-rates exceeding 108 M-1s-1 can be quantified, and folding-related phenomena can be directly resolved, switchSENSE is a useful analytical tool for in-depth characterization of aptamer-ion and aptamer-protein interactions.
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Gao R, Lin Y, Ying YL, Long YT. Nanopore-based sensing interface for single molecule electrochemistry. Sci China Chem 2019. [DOI: 10.1007/s11426-019-9509-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Vu T, Borgesi J, Soyring J, D'Alia M, Davidson SL, Shim J. Employing LiCl salt gradient in the wild-type α-hemolysin nanopore to slow down DNA translocation and detect methylated cytosine. NANOSCALE 2019; 11:10536-10545. [PMID: 31116213 DOI: 10.1039/c9nr00502a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this research, we demonstrate a label-free detection, biological nanopore-based method to distinguish methylated cytosine (mC) from naked cytosine (C) in sample mixtures containing both C and mC at a prolonged translocation duration. Using a 15-fold increase in LiCl salt concentration going from a cis to trans chamber, we increased the translocation dwell time of ssDNA by over 5-fold and the event capture rate by 6-fold in comparison with the symmetric concentration of 1.0 M KCl (control). This is a consequence of counter-ion binding and effective lowering of the overall charge of DNA, which in turn lessens the electrophoretic drive of the system and slows the translocation velocity. Moreover, salt gradients can create a large electric field that will funnel ions and polymers towards the pore, increasing the capture rate and translocation dwell time of DNA. As a result, in 0.2 M-3.0 M LiCl solution, ssDNA achieved a prolonged dwell time of 52 μs per nucleotide and a capture rate of 60 ssDNA per second. Importantly, lowering the translocation speed of ssDNA enhances the resulting resolution, allowing 5'-mC to be distinguished from C without using methyl-specific labels. We successfully distinguished 5'-mC from C when mixed together at ratios of 1 : 1, 3 : 7 and 7 : 3. The distribution of current blockade amplitudes of all mixtures adopted bimodal shapes, with peak-to-peak ratios coarsely corresponding to the mixture composition (e.g. the density and distribution of events shifted in correspondence with changes in 18b-0mC and 18-2mC concentration ratios in the mixture).
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Affiliation(s)
- Trang Vu
- Department of Biomedical Engineering, Rowan University, Glassboro, NJ 08028, USA.
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Bian Y, Song F, Cao Z, Zhao L, Yu J, Guo X, Wang J. Fast-Folding Pathways of the Thrombin-Binding Aptamer G-Quadruplex Revealed by a Markov State Model. Biophys J 2019; 114:1529-1538. [PMID: 29642024 DOI: 10.1016/j.bpj.2018.02.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 12/31/2022] Open
Abstract
G-quadruplex structures participate in many important cellular processes. For a better understanding of their functions, knowledge of the mechanism by which they fold into the functional native structures is necessary. In this work, we studied the folding process of the thrombin-binding aptamer G-quadruplex. Enabled by a computational paradigm that couples an advanced sampling method and a Markov state model, four folding intermediates were identified, including an antiparallel G-hairpin, two G-triplex structures, and a double-hairpin conformation. Likewise, a misfolded structure with a nonnative distribution of syn/anti guanines was also observed. Based on these states, a transition path analysis revealed three fast-folding pathways, along which the thrombin-binding aptamer would fold to the native state directly, with no evidence of potential nonnative competing conformations. The results also showed that the TGT-loop plays an important role in the folding process. The findings of this research may provide general insight about the folding of other G-quadruplex structures.
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Affiliation(s)
- Yunqiang Bian
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, China.
| | - Feng Song
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, China
| | - Zanxia Cao
- Department of Physics, Dezhou University, Dezhou, China
| | - Liling Zhao
- Department of Physics, Dezhou University, Dezhou, China
| | - Jiafeng Yu
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, China
| | - Xinlu Guo
- Wuxi Vocational Institute of Commerce, Wuxi, China; Taihu University of Wuxi, Wuxi, China
| | - Jihua Wang
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, China; Department of Physics, Dezhou University, Dezhou, China.
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Vu T, Davidson SL, Shim J. Investigation of compacted DNA structures induced by Na + and K + monovalent cations using biological nanopores. Analyst 2019; 143:906-913. [PMID: 29362734 DOI: 10.1039/c7an01857f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In aqueous solutions, an elongated, negatively charged DNA chain can quickly change its conformation into a compacted globule in the presence of positively charged molecules, or cations. This well-known process, called DNA compaction, is a method with great potential for gene therapy and delivery. Experimental conditions to induce these compacted DNA structures are often limited to the use of common compacting agents, such as cationic surfactants, polymers, and multivalent cations. In this study, we show that in highly concentrated buffers of 1 M monovalent cation solutions at pH 7.2 and 10, biological nanopores allow real-time sensing of individual compacted structures induced by K+ and Na+, the most abundant monovalent cations in human bodies. Herein, we studied the ratio between compacted and linear structures for 15-mer single-stranded DNA molecules containing only cytosine nucleotides, optimizing the probability of linear DNA chains being compacted. Since the binding affinity of each nucleotide to cation is different, the ability of the DNA strand to fold into a compacted structure greatly depends on the type of cations and nucleotides present. Our experimental results compare favorably with findings from previous molecular dynamics simulations for the DNA compacting potential of K+ and Na+ monovalent cations. We estimate that the majority of single-stranded DNA molecules in our experiment are compacted. From the current traces of nanopores, the ratio of compacted DNA to linear DNA molecules is approximately 30 : 1 and 15 : 1, at a pH of 7.2 and 10, respectively. Our comparative studies reveal that Na+ monovalent cations have a greater potential of compacting the 15C-ssDNA than K+ cations.
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Affiliation(s)
- Trang Vu
- Department of Biomedical Engineering, Rowan University, Glassboro, New Jersey 08028, USA.
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Goto Y, Yanagi I, Matsui K, Yokoi T, Takeda KI. Identification of four single-stranded DNA homopolymers with a solid-state nanopore in alkaline CsCl solution. NANOSCALE 2018; 10:20844-20850. [PMID: 30403221 DOI: 10.1039/c8nr04238a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
DNA sequencing via solid-state nanopores is a promising technique with the potential to surpass the performance of conventional sequencers. However, the identification of all four nucleotide homopolymers with a typical SiN nanopore is yet to be clearly demonstrated because a guanine homopolymer rapidly forms a G-quadruplex in a typical KCl aqueous solution. To address this issue, we introduced an alkaline CsCl aqueous solution, which denatures the G-quadruplex into a single-stranded structure by disrupting the hydrogen-bonding network between the guanines and preventing the binding of the K+ ion to G-quartets. Using this alkaline CsCl solution, we provided a proof-of-principle that single-stranded DNA homopolymers of all four nucleotides could be statistically identified according to their blockade currents with the same single nanopore. We also confirmed that a triblock DNA copolymer of three nucleotides exhibited a trimodal Gaussian distribution whose peaks correspond to those of the DNA homopolymers. Our findings contribute to the development of practical DNA sequencing with a solid-state nanopore.
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Affiliation(s)
- Yusuke Goto
- Center for Technology Innovation - Healthcare, Research & Development Group, Hitachi Ltd, 1-280 Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan.
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Tian K, Chen X, Luan B, Singh P, Yang Z, Gates KS, Lin M, Mustapha A, Gu LQ. Single Locked Nucleic Acid-Enhanced Nanopore Genetic Discrimination of Pathogenic Serotypes and Cancer Driver Mutations. ACS NANO 2018; 12:4194-4205. [PMID: 29664612 PMCID: PMC6157732 DOI: 10.1021/acsnano.8b01198] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Accurate and rapid detection of single-nucleotide polymorphism (SNP) in pathogenic mutants is crucial for many fields such as food safety regulation and disease diagnostics. Current detection methods involve laborious sample preparations and expensive characterizations. Here, we investigated a single locked nucleic acid (LNA) approach, facilitated by a nanopore single-molecule sensor, to accurately determine SNPs for detection of Shiga toxin producing Escherichia coli (STEC) serotype O157:H7, and cancer-derived EGFR L858R and KRAS G12D driver mutations. Current LNA applications that require incorporation and optimization of multiple LNA nucleotides. But we found that in the nanopore system, a single LNA introduced in the probe is sufficient to enhance the SNP discrimination capability by over 10-fold, allowing accurate detection of the pathogenic mutant DNA mixed in a large amount of the wild-type DNA. Importantly, the molecular mechanistic study suggests that such a significant improvement is due to the effect of the single-LNA that both stabilizes the fully matched base-pair and destabilizes the mismatched base-pair. This sensitive method, with a simplified, low cost, easy-to-operate LNA design, could be generalized for various applications that need rapid and accurate identification of single-nucleotide variations.
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Affiliation(s)
- Kai Tian
- Department of Bioengineering and Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Xiaowei Chen
- Food Science Program, Division of Food Systems and Bioengineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Binquan Luan
- Computational Biology Center, IBM Thomas J. Watson Research, Yorktown Heights, New York 10598, United States
| | - Prashant Singh
- Food Science Program, Division of Food Systems and Bioengineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Zhiyu Yang
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Kent S. Gates
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Mengshi Lin
- Food Science Program, Division of Food Systems and Bioengineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Azlin Mustapha
- Food Science Program, Division of Food Systems and Bioengineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Li-Qun Gu
- Department of Bioengineering and Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri 65211, United States
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36
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Liao DF, Cao C, Ying YL, Long YT. A General Strategy of Aerolysin Nanopore Detection for Oligonucleotides with the Secondary Structure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1704520. [PMID: 29603609 DOI: 10.1002/smll.201704520] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/01/2018] [Indexed: 06/08/2023]
Abstract
An aerolysin nanopore is employed as a sensitive tool for single-molecule analysis of short oligonucleotides (≤10 nucleotides), poly(ethylene glycol) (PEGs), peptides, and proteins. However, the direct analysis of long oligonucleotides with the secondary structure (e.g., G-quadruplex topology) remains a challenge, which impedes the further practical applications of the aerolysin nanopore. Here, a simple and applicable method of aerolysin nanopore is presented to achieve a direct analysis of structured oligonucleotides that are extended to 30 nucleotides long by a cation-regulation mechanism. By regulating the cation type in electrolyte solution, the structured oligonucleotides are unfolded into linear form which ensures the successive translocation. The results show that each model oligonucleotide of 5'-(TTAGGG)n -3' can produce a well-resolved current blockade in its unfolded solution of MgCl2 . The length between 6 and 30 nucleotides long of model oligonucleotides is proportional to the duration time, showing a translocation velocity as low as 0.70-0.13 ms nt-1 at +140 mV. This method exhibits an excellent sensitivity and a sufficient temporal resolution, provides insight into the aerolysin nanopore methodology for genetic and epigenetic biosensing, making aerolysin applicable in practical diagnosing with long and structured nucleic acids.
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Affiliation(s)
- Dong-Fang Liao
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China
| | - Chan Cao
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China
| | - Yi-Lun Ying
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China
| | - Yi-Tao Long
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China
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Cai H, Zhou C, Yang Q, Ai T, Huang Y, Lv Y, Geng J, Xiao D. Single-molecule investigation of human telomeric G-quadruplex interactions with Thioflavin T. CHINESE CHEM LETT 2018. [DOI: 10.1016/j.cclet.2017.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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38
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Yang C, Kulkarni M, Lim M, Pak Y. Insilico direct folding of thrombin-binding aptamer G-quadruplex at all-atom level. Nucleic Acids Res 2017; 45:12648-12656. [PMID: 29112755 PMCID: PMC5728390 DOI: 10.1093/nar/gkx1079] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/13/2017] [Accepted: 10/20/2017] [Indexed: 12/25/2022] Open
Abstract
The reversible folding of the thrombin-binding DNA aptamer G-quadruplexes (GQs) (TBA-15) starting from fully unfolded states was demonstrated using a prolonged time scale (10-12 μs) parallel tempering metadynamics (PTMetaD) simulation method in conjunction with a modified version of the AMBER bsc1 force field. For unbiased descriptions of the folding free energy landscape of TBA-15, this force field was minimally modified. From this direct folding simulation using the modified bsc1 force field, reasonably converged free energy landscapes were obtained in K+-rich aqueous solution (150 mM), providing detailed atomistic pictures of GQ folding mechanisms for TBA-15. This study found that the TBA folding occurred via multiple folding pathways with two major free energy barriers of 13 and 15 kcal/mol in the presence of several intermediate states of G-triplex variants. The early formation of these intermediates was associated with a single K+ ion capturing. Interestingly, these intermediate states appear to undergo facile transitions among themselves through relatively small energy barriers.
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Affiliation(s)
- Changwon Yang
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
| | - Mandar Kulkarni
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
| | - Manho Lim
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
| | - Youngshang Pak
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
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YANG J, LI S, WU XY, LONG YT. Development of Biological Nanopore Technique in Non-gene Sequencing Application. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2017. [DOI: 10.1016/s1872-2040(17)61053-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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40
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Huang G, Willems K, Soskine M, Wloka C, Maglia G. Electro-osmotic capture and ionic discrimination of peptide and protein biomarkers with FraC nanopores. Nat Commun 2017; 8:935. [PMID: 29038539 PMCID: PMC5715100 DOI: 10.1038/s41467-017-01006-4] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/09/2017] [Indexed: 12/13/2022] Open
Abstract
Biological nanopores are nanoscale sensors employed for high-throughput, low-cost, and long read-length DNA sequencing applications. The analysis and sequencing of proteins, however, is complicated by their folded structure and non-uniform charge. Here we show that an electro-osmotic flow through Fragaceatoxin C (FraC) nanopores can be engineered to allow the entry of polypeptides at a fixed potential regardless of the charge composition of the polypeptide. We further use the nanopore currents to discriminate peptide and protein biomarkers from 25 kDa down to 1.2 kDa including polypeptides differing by one amino acid. On the road to nanopore proteomics, our findings represent a rationale for amino-acid analysis of folded and unfolded polypeptides with nanopores. Biological nanopore–based protein sequencing and recognition is challenging due to the folded structure or non-uniform charge of peptides. Here the authors show that engineered FraC nanopores can overcome these problems and recognize biomarkers in the form of oligopeptides, polypeptides and folded proteins.
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Affiliation(s)
- Gang Huang
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Kherim Willems
- KU Leuven Department of Chemistry, Celestijnenlaan 200G, 3001, Leuven, Belgium.,Imec, Kapeldreef 75, 3001, Leuven, Belgium
| | - Misha Soskine
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Carsten Wloka
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands.
| | - Giovanni Maglia
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands.
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41
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Lipid bilayer membrane technologies: A review on single-molecule studies of DNA sequencing by using membrane nanopores. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2321-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
Telomeres are specialized chromatin structures that protect chromosome ends from dangerous processing events. In most tissues, telomeres shorten with each round of cell division, placing a finite limit on cell growth. In rapidly dividing cells, including the majority of human cancers, cells bypass this growth limit through telomerase-catalyzed maintenance of telomere length. The dynamic properties of telomeres and telomerase render them difficult to study using ensemble biochemical and structural techniques. This review describes single-molecule approaches to studying how individual components of telomeres and telomerase contribute to function. Single-molecule methods provide a window into the complex nature of telomeres and telomerase by permitting researchers to directly visualize and manipulate the individual protein, DNA, and RNA molecules required for telomere function. The work reviewed in this article highlights how single-molecule techniques have been utilized to investigate the function of telomeres and telomerase.
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Affiliation(s)
- Joseph W Parks
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064; .,Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80303
| | - Michael D Stone
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064; .,Center for Molecular Biology of RNA, Santa Cruz, California 95064
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43
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Rauf S, Zhang L, Ali A, Liu Y, Li J. Label-Free Nanopore Biosensor for Rapid and Highly Sensitive Cocaine Detection in Complex Biological Fluids. ACS Sens 2017; 2:227-234. [PMID: 28723133 DOI: 10.1021/acssensors.6b00627] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Detection of very low amounts of illicit drugs such as cocaine in clinical fluids like serum continues to be important for many areas in the fight against drug trafficking. Herein, we constructed a label-free nanopore biosensor for rapid and highly sensitive detection of cocaine in human serum and saliva samples based on target-induced strand release strategy. In this bioassay, an aptamer for cocaine was prehybridized with a short complementary DNA. Owing to cocaine specific binding with aptamer, the short DNA strand was displaced from aptamer and translocation of this output DNA through α-hemolysin nanopore generated distinct spike-like current blockages. When plotted in double-logarithmic scale, a linear relationship between target cocaine concentration and output DNA event frequency was obtained in a wide concentration range from 50 nM to 100 μM of cocaine, with the limit of detection down to 50 nM. In addition, this aptamer-based sensor method was successfully applied for cocaine detection in complex biological fluids like human saliva and serum samples with great selectivity. Simple preparation, low cost, rapid, label-free, and real sample detection are the motivating factors for practical application of the proposed biosensor.
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Affiliation(s)
- Sana Rauf
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Ling Zhang
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Asghar Ali
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Yang Liu
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Jinghong Li
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
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44
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Vu T, Davidson SL, Borgesi J, Maksudul M, Jeon TJ, Shim J. Piecing together the puzzle: nanopore technology in detection and quantification of cancer biomarkers. RSC Adv 2017. [DOI: 10.1039/c7ra08063h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This mini-review paper is a comprehensive outline of nanopore technology applications in the detection and study of various cancer causal factors.
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Affiliation(s)
- Trang Vu
- Department of Biomedical Engineering
- Henry M. Rowan College of Engineering
- Rowan University
- Glassboro
- USA
| | - Shanna-Leigh Davidson
- Department of Biomedical Engineering
- Henry M. Rowan College of Engineering
- Rowan University
- Glassboro
- USA
| | - Julia Borgesi
- Department of Biomedical Engineering
- Henry M. Rowan College of Engineering
- Rowan University
- Glassboro
- USA
| | - Mowla Maksudul
- Department of Biomedical Engineering
- Henry M. Rowan College of Engineering
- Rowan University
- Glassboro
- USA
| | - Tae-Joon Jeon
- Department of Biological Engineering
- Inha University
- Incheon 22212
- Republic of Korea
| | - Jiwook Shim
- Department of Biomedical Engineering
- Henry M. Rowan College of Engineering
- Rowan University
- Glassboro
- USA
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45
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Reddy GNM, Huqi A, Iuga D, Sakurai S, Marsh A, Davis JT, Masiero S, Brown SP. Co-existence of Distinct Supramolecular Assemblies in Solution and in the Solid State. Chemistry 2016; 23:2315-2322. [PMID: 27897351 PMCID: PMC5396329 DOI: 10.1002/chem.201604832] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Indexed: 11/24/2022]
Abstract
The formation of distinct supramolecular assemblies, including a metastable species, is revealed for a lipophilic guanosine (G) derivative in solution and in the solid state. Structurally different G‐quartet‐based assemblies are formed in chloroform depending on the nature of the cation, anion and the salt concentration, as characterized by circular dichroism and time course diffusion‐ordered NMR spectroscopy data. Intriguingly, even the presence of potassium ions that stabilize G‐quartets in chloroform was insufficient to exclusively retain such assemblies in the solid state, leading to the formation of mixed quartet and ribbon‐like assemblies as revealed by fast magic‐angle spinning (MAS) NMR spectroscopy. Distinct N−H⋅⋅⋅N and N−H⋅⋅⋅O intermolecular hydrogen bonding interactions drive quartet and ribbon‐like self‐assembly resulting in markedly different 2D 1H solid‐state NMR spectra, thus facilitating a direct identification of mixed assemblies. A dissolution NMR experiment confirmed that the quartet and ribbon interconversion is reversible–further demonstrating the changes that occur in the self‐assembly process of a lipophilic nucleoside upon a solid‐state to solution‐state transition and vice versa. A systematic study for complexation with different cations (K+, Sr2+) and anions (picrate, ethanoate and iodide) emphasizes that the existence of a stable solution or solid‐state structure may not reflect the stability of the same supramolecular entity in another phase.
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Affiliation(s)
- G N Manjunatha Reddy
- Department of Physics and Department of Chemistry, University of, Warwick, Coventry, CV4 7AL, UK
| | - Aida Huqi
- Dipartimento di Chimica "Giacomo Ciamician", Alma Mater Studiorum, Università di Bologna, 40126, Bologna, Italy
| | - Dinu Iuga
- Department of Physics and Department of Chemistry, University of, Warwick, Coventry, CV4 7AL, UK
| | - Satoshi Sakurai
- JEOL (UK), Silver Court, Watchmead, Welwyn Garden City, AL7 1LT, UK
| | - Andrew Marsh
- Department of Physics and Department of Chemistry, University of, Warwick, Coventry, CV4 7AL, UK
| | - Jeffery T Davis
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Stefano Masiero
- Dipartimento di Chimica "Giacomo Ciamician", Alma Mater Studiorum, Università di Bologna, 40126, Bologna, Italy
| | - Steven P Brown
- Department of Physics and Department of Chemistry, University of, Warwick, Coventry, CV4 7AL, UK
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Shen G, Zhang H, Yang C, Yang Q, Tang Y. Thrombin Ultrasensitive Detection Based on Chiral Supramolecular Assembly Signal-Amplified Strategy Induced by Thrombin-Binding Aptamer. Anal Chem 2016; 89:548-551. [PMID: 27958723 DOI: 10.1021/acs.analchem.6b04247] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Thrombin plays a critical role in hemostasis and hemolysis. It is of high importance to develop a system toward thrombin detection with high sensitivity and high selectivity for both research and clinical diagnosis applications. In this paper, we developed a thrombin detection assay by taking advantage of the novel signal amplified strategy based on the chiral supramolecular assembly in physiological K+ background. This assay could detect thrombin as low concentration as about 2 pM and provided a highly specific selectivity among several common interferences. Furthermore, the assay can discriminate thrombin from other nonspecific analogous proteins with high selectivity and can be used to detect thrombin in diluted real human serum samples, which suggested its great potential for rapid detection of thrombin in the clinic.
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Affiliation(s)
- Gang Shen
- National Laboratory for Molecular Sciences, Centre for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
| | - Hong Zhang
- National Laboratory for Molecular Sciences, Centre for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
| | - Chunrong Yang
- College of Chemistry, Sichuan University , Chengdu, 610065, China
| | - Qianfan Yang
- College of Chemistry, Sichuan University , Chengdu, 610065, China
| | - Yalin Tang
- National Laboratory for Molecular Sciences, Centre for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
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Perera RT, Fleming AM, Peterson AM, Heemstra JM, Burrows CJ, White HS. Unzipping of A-Form DNA-RNA, A-Form DNA-PNA, and B-Form DNA-DNA in the α-Hemolysin Nanopore. Biophys J 2016; 110:306-314. [PMID: 26789754 DOI: 10.1016/j.bpj.2015.11.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/03/2015] [Accepted: 11/16/2015] [Indexed: 01/04/2023] Open
Abstract
Unzipping of double-stranded nucleic acids by an electric field applied across a wild-type α-hemolysin (αHL) nanopore provides structural information about different duplex forms. In this work, comparative studies on A-form DNA-RNA duplexes and B-form DNA-DNA duplexes with a single-stranded tail identified significant differences in the blockage current and the unzipping duration between the two helical forms. We observed that the B-form duplex blocks the channel 1.9 ± 0.2 pA more and unzips ∼15-fold more slowly than an A-form duplex at 120 mV. We developed a model to describe the dependence of duplex unzipping on structure. We demonstrate that the wider A-form duplex (d = 2.4 nm) is unable to enter the vestibule opening of αHL on the cis side, leading to unzipping outside of the nanopore with higher residual current and faster unzipping times. In contrast, the smaller B-form duplexes (d = 2.0 nm) enter the vestibule of αHL, resulting in decreased current blockages and slower unzipping. We investigated the effects of varying the length of the single-stranded overhang, and studied A-form DNA-PNA duplexes to provide additional support for the proposed model. This study identifies key differences between A- and B-form duplex unzipping that will be important in the design of future probe-based methods for detecting DNA or RNA.
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Affiliation(s)
- Rukshan T Perera
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - Aaron M Fleming
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | | | | | | | - Henry S White
- Department of Chemistry, University of Utah, Salt Lake City, Utah.
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Distinct differences in metal ion specificity of RNA and DNA G-quadruplexes. J Biol Inorg Chem 2016; 21:975-986. [PMID: 27704222 DOI: 10.1007/s00775-016-1393-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 09/02/2016] [Indexed: 01/21/2023]
Abstract
RNA G-quadruplexes, as their well-studied DNA analogs, require the presence of cations to fold and remain stable. This is the first comprehensive study on the interaction of RNA quadruplexes with metal ions. We investigated the formation and stability of two highly conserved and biologically relevant RNA quadruplex-forming sequences (24nt-TERRA and 18nt-NRAS) in the presence of several monovalent and divalent metal ions, namely Li+, Na+, K+, Rb+, Cs+, NH4+, Mg2+, Ca2+, Sr2+, and Ba2+. Circular dichroism was used to probe the influence of these metal ions on the folded fraction of the parallel G-quadruplexes, and UV thermal melting experiments allowed to assess the relative stability of the structures in each cationic condition. Our results show that the RNA quadruplexes are more stable than their DNA counterparts under the same buffer conditions. We have observed that the addition of mainly Na+, K+, Rb+, NH4+, as well as Sr2+ and Ba2+ in water, shifts the equilibrium to the folded quadruplex form, whereby the NRAS sequence responds stronger than TERRA. However, only K+ and Sr2+ lead to a significant increase in the stability of the folded structures, which is consistent with their coordination to the O6 atoms from the G-quartet guanosines. Compared to the respective DNA motives, dNRAS and htelo, the RNA sequences are not stabilized by Na+ ions. Finally, the difference in response between NRAS and TERRA, as well as to the corresponding DNA sequences with respect to different metal ions, could potentially be exploited for selective targeting purposes.
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49
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Liu L, Wu HC. DNA-Based Nanopore Sensing. Angew Chem Int Ed Engl 2016; 55:15216-15222. [DOI: 10.1002/anie.201604405] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/13/2016] [Indexed: 01/09/2023]
Affiliation(s)
- Lei Liu
- Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, Institute of High Energy Physics; Chinese Academy of Sciences; Beijing 100049 China
| | - Hai-Chen Wu
- Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, Institute of High Energy Physics; Chinese Academy of Sciences; Beijing 100049 China
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 China
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Affiliation(s)
- Lei Liu
- Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety; Institute of High Energy Physics; Chinese Academy of Sciences; Peking 100049 China
| | - Hai-Chen Wu
- Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety; Institute of High Energy Physics; Chinese Academy of Sciences; Peking 100049 China
- Beijing National Laboratory for Molecular Sciences; Key Laboratory of Analytical Chemistry for Living Biosystems; Institute of Chemistry; Chinese Academy of Sciences; Peking 100190 China
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