1
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Mereuta L, Bhatti H, Asandei A, Cimpanu A, Ying YL, Long YT, Luchian T. Controlling DNA Fragments Translocation across Nanopores with the Synergic Use of Site-Directed Mutagenesis, pH-Dependent Charge Tuning, and Electroosmotic Flow. ACS APPLIED MATERIALS & INTERFACES 2024; 16:40100-40110. [PMID: 39038810 PMCID: PMC11299134 DOI: 10.1021/acsami.4c03848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 07/09/2024] [Accepted: 07/14/2024] [Indexed: 07/24/2024]
Abstract
Biological and solid-state nanopores are at the core of transformative techniques and nanodevices, democratizing the examination of matter and biochemical reactions at the single-molecule level, with low cost, portability, and simplicity in operation. One of the crucial hurdles in such endeavors is the fast analyte translocation, which limits characterization, and a rich number of strategies have been explored over the years to overcome this. Here, by site-directed mutagenesis on the α-hemolysin protein nanopore (α-HL), sought to replace selected amino acids with glycine, electrostatic binding sites were induced on the nanopore's vestibule and constriction region and achieved in the most favorable case a 20-fold increase in the translocation time of short single-stranded DNA (ssDNA) at neutral pH, with respect to the wild-type (WT) nanopore. We demonstrated an efficient tool of controlling the ssDNA translocation time, via the interplay between the nanopore-ssDNA surface electrostatic interactions and electroosmotic flow, all mediated by the pH-dependent ionization of amino acids lining the nanopore's translocation pathway. Our data also reveal the nonmonotonic, pH-induced alteration of ssDNA average translocation time. Unlike mildly acidic conditions (pH ∼ 4.7), at a pH ∼ 2.8 maintained symmetrically or asymmetrically across the WT α-HL, we evidenced the manifestation of a dominant electroosmotic flow, determining the speeding up of the ssDNA translocation across the nanopore by counteracting the ssDNA-nanopore attractive electrostatic interactions. We envision potential applications of the presented approach by enabling easy-to-use, real-time detection of short ssDNA sequences, without the need for complex biochemical modifications to the nanopore to mitigate the fast translocation of such sequences.
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Affiliation(s)
- Loredana Mereuta
- Department
of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania
| | - Huma Bhatti
- Molecular
Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China
| | - Alina Asandei
- Interdisciplinary
Research Institute, Sciences Department, Alexandru I. Cuza University, 700506 Iasi, Romania
| | - Adina Cimpanu
- Department
of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania
| | - Yi-Lun Ying
- Molecular
Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China
| | - Yi-Tao Long
- Molecular
Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China
| | - Tudor Luchian
- Department
of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania
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2
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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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3
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Mereuta L, Asandei A, Andricioaei I, Park J, Park Y, Luchian T. Considerable slowdown of short DNA fragment translocation across a protein nanopore using pH-induced generation of enthalpic traps inside the permeation pathway. NANOSCALE 2023; 15:14754-14763. [PMID: 37655668 DOI: 10.1039/d3nr03344a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
A pressing challenge in the realm of nanopore-based sensing technologies for nucleic acid characterization has been the cheap and efficient control of analyte translocation. To address this, a plethora of methods were tested, including mutagenesis, molecular motors, enzymes, or the optimization of experimental conditions. Herein, we present a paradigm exploiting the manipulation of electrostatic interactions between 22-mer single-stranded DNAs (22_ssDNA) and low pH-induced charges in the alpha-hemolysin (α-HL) nanopore, to efficiently control the passage of captured molecules. We discovered that in electrolytes buffered at pH = 5 and pH = 4.5 where the nanopore's vestibule and lumen become oppositely charged as compared to that at neutral pH, the electrostatic anchoring at these regions of a 22_ssDNA fragment leads to a dramatic increase of the translocation time, orders of magnitude larger compared to that at neutral pH. This pH-dependent tethering effect is reversible, side invariant, and sensitive to the ionic strength and ssDNA contour length. In the long run, our discovery has the potential to provide a simple read-out of the sequence of bases pertaining to short nucleotide sequences, thus extending the efficacy of current nanopore-based sequencers.
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Affiliation(s)
- Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania.
| | - Alina Asandei
- Interdisciplinary Research Institute, Sciences Department, Alexandru I. Cuza University, 700506 Iasi, Romania
| | - Ioan Andricioaei
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, CA 92617, USA
| | - Jonggwan Park
- Department of Bioinformatics, Kongju National University, Kongju, 32588, Republic of Korea
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, 61452, Republic of Korea.
| | - Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania.
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4
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Zalar M, Wang B, Plavec J, Šket P. Insight into Tetramolecular DNA G-Quadruplexes Associated with ALS and FTLD: Cation Interactions and Formation of Higher-Ordered Structure. Int J Mol Sci 2023; 24:13437. [PMID: 37686239 PMCID: PMC10487854 DOI: 10.3390/ijms241713437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The G4C2 hexanucleotide repeat expansion in the c9orf72 gene is a major genetic cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), with the formation of G-quadruplexes directly linked to the development of these diseases. Cations play a crucial role in the formation and structure of G-quadruplexes. In this study, we investigated the impact of biologically relevant potassium ions on G-quadruplex structures and utilized 15N-labeled ammonium cations as a substitute for K+ ions to gain further insights into cation binding and exchange dynamics. Through nuclear magnetic resonance spectroscopy and molecular dynamics simulations, we demonstrate that the single d(G4C2) repeat, in the presence of 15NH4+ ions, adopts a tetramolecular G-quadruplex with an all-syn quartet at the 5'-end. The movement of 15NH4+ ions through the central channel of the G-quadruplex, as well as to the bulk solution, is governed by the vacant cation binding site, in addition to the all-syn quartet at the 5'-end. Furthermore, the addition of K+ ions to G-quadruplexes folded in the presence of 15NH4+ ions induces stacking of G-quadruplexes via their 5'-end G-quartets, leading to the formation of stable higher-ordered species.
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Affiliation(s)
- Matja Zalar
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
| | - Baifan Wang
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
- EN-FIST Center of Excellence, Trg OF 13, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
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5
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Mustafa G, Gyawali P, Taylor JA, Maleki P, Nunez MV, Guntrum MC, Shiekh S, Balci H. A single molecule investigation of i-motif stability, folding intermediates, and potential as in-situ pH sensor. Front Mol Biosci 2022; 9:977113. [PMID: 36072435 PMCID: PMC9441956 DOI: 10.3389/fmolb.2022.977113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
We present a collection of single molecule work on the i-motif structure formed by the human telomeric sequence. Even though it was largely ignored in earlier years of its discovery due to its modest stability and requirement for low pH levels (pH < 6.5), the i-motif has been attracting more attention recently as both a physiologically relevant structure and as a potent pH sensor. In this manuscript, we establish single molecule Förster resonance energy transfer (smFRET) as a tool to study the i-motif over a broad pH and ionic conditions. We demonstrate pH and salt dependence of i-motif formation under steady state conditions and illustrate the intermediate states visited during i-motif folding in real time at the single molecule level. We also show the prominence of intermediate folding states and reversible folding/unfolding transitions. We present an example of using the i-motif as an in-situ pH sensor and use this sensor to establish the time scale for the pH drop in a commonly used oxygen scavenging system.
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Affiliation(s)
| | | | | | | | | | | | | | - Hamza Balci
- Department of Physics, Kent State University, Kent, OH, United States
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6
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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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7
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Cascade i-motifs-dependent reversible electrochemical impedance strategy-oriented pH and terminal deoxynucleotidyl transferase biosensing. Bioelectrochemistry 2022; 145:108085. [DOI: 10.1016/j.bioelechem.2022.108085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/29/2022] [Accepted: 02/07/2022] [Indexed: 01/21/2023]
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8
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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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9
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Lin B, Hui J, Mao H. Nanopore Technology and Its Applications in Gene Sequencing. BIOSENSORS-BASEL 2021; 11:bios11070214. [PMID: 34208844 PMCID: PMC8301755 DOI: 10.3390/bios11070214] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/22/2021] [Accepted: 06/25/2021] [Indexed: 12/14/2022]
Abstract
In recent years, nanopore technology has become increasingly important in the field of life science and biomedical research. By embedding a nano-scale hole in a thin membrane and measuring the electrochemical signal, nanopore technology can be used to investigate the nucleic acids and other biomacromolecules. One of the most successful applications of nanopore technology, the Oxford Nanopore Technology, marks the beginning of the fourth generation of gene sequencing technology. In this review, the operational principle and the technology for signal processing of the nanopore gene sequencing are documented. Moreover, this review focuses on the applications using nanopore gene sequencing technology, including the diagnosis of cancer, detection of viruses and other microbes, and the assembly of genomes. These applications show that nanopore technology is promising in the field of biological and biomedical sensing.
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Affiliation(s)
- Bo Lin
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (B.L.); (J.H.)
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianan Hui
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (B.L.); (J.H.)
| | - Hongju Mao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; (B.L.); (J.H.)
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: ; Tel.: +86-21-62511070-8707
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10
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Affiliation(s)
- Mengjie Cui
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
| | - Yaxian Ge
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
| | - Xiao Zhuge
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
| | - Xin Zhou
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
| | - Dongmei Xi
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
| | - Shusheng Zhang
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University Linyi Shandong 276005 China
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11
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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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12
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Yin YD, Zhang L, Leng XZ, Gu ZY. Harnessing biological nanopore technology to track chemical changes. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Niu X, Liu Q, Xu Z, Chen Z, Xu L, Xu L, Li J, Fang X. Molecular mechanisms underlying the extreme mechanical anisotropy of the flaviviral exoribonuclease-resistant RNAs (xrRNAs). Nat Commun 2020; 11:5496. [PMID: 33127896 PMCID: PMC7603331 DOI: 10.1038/s41467-020-19260-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 10/07/2020] [Indexed: 02/06/2023] Open
Abstract
Mechanical anisotropy is an essential property for many biomolecules to assume their structures, functions and applications, however, the mechanisms for their direction-dependent mechanical responses remain elusive. Herein, by using a single-molecule nanopore sensing technique, we explore the mechanisms of directional mechanical stability of the xrRNA1 RNA from ZIKA virus (ZIKV), which forms a complex ring-like architecture. We reveal extreme mechanical anisotropy in ZIKV xrRNA1 which highly depends on Mg2+ and the key tertiary interactions. The absence of Mg2+ and disruption of the key tertiary interactions strongly affect the structural integrity and attenuate mechanical anisotropy. The significance of ring structures in RNA mechanical anisotropy is further supported by steered molecular dynamics simulations in combination with force distribution analysis. We anticipate the ring structures can be used as key elements to build RNA-based nanostructures with controllable mechanical anisotropy for biomaterial and biomedical applications.
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Affiliation(s)
- Xiaolin Niu
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiuhan Liu
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Zhonghe Xu
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhifeng Chen
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Linghui Xu
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Lilei Xu
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jinghong Li
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
| | - Xianyang Fang
- Beijing Advanced Innovation Center for Structfural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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14
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Rogers RA, Meyer MR, Stewart KM, Eyring GM, Fleming AM, Burrows CJ. Hysteresis in poly-2'-deoxycytidine i-motif folding is impacted by the method of analysis as well as loop and stem lengths. Biopolymers 2020; 112:e23389. [PMID: 33098582 DOI: 10.1002/bip.23389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/06/2020] [Accepted: 06/11/2020] [Indexed: 02/06/2023]
Abstract
In DNA, i-motif (iM) folds occur under slightly acidic conditions when sequences rich in 2'-deoxycytidine (dC) nucleotides adopt consecutive dC self base pairs. The pH stability of an iM is defined by the midpoint in the pH transition (pHT ) between the folded and unfolded states. Two different experiments to determine pHT values via circular dichroism (CD) spectroscopy were performed on poly-dC iMs of length 15, 19, or 23 nucleotides. These experiments demonstrate two points: (1) pHT values were dependent on the titration experiment performed, and (2) pH-induced denaturing or annealing processes produced isothermal hysteresis in the pHT values. These results in tandem with model iMs with judicious mutations of dC to thymidine to favor particular folds found the hysteresis was maximal for the shorter poly-dC iMs and those with an even number of base pairs, while the hysteresis was minimal for longer poly-dC iMs and those with an odd number of base pairs. Experiments to follow the iM folding via thermal changes identified thermal hysteresis between the denaturing and annealing cycles. Similar trends were found to those observed in the CD experiments. The results demonstrate that the method of iM analysis can impact the pHT parameter measured, and hysteresis was observed in the pHT and Tm values.
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Affiliation(s)
- R Aaron Rogers
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
| | - Madeline R Meyer
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
| | - Kayla M Stewart
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
| | - Gabriela M Eyring
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
| | - Aaron M Fleming
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, Salt Lake City, Utah, U.S.A
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15
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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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16
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Megalathan A, Cox BD, Wilkerson PD, Kaur A, Sapkota K, Reiner JE, Dhakal S. Single-molecule analysis of i-motif within self-assembled DNA duplexes and nanocircles. Nucleic Acids Res 2019; 47:7199-7212. [PMID: 31287873 PMCID: PMC6698746 DOI: 10.1093/nar/gkz565] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 06/13/2019] [Accepted: 07/04/2019] [Indexed: 12/20/2022] Open
Abstract
The cytosine (C)-rich sequences that can fold into tetraplex structures known as i-motif are prevalent in genomic DNA. Recent studies of i-motif-forming sequences have shown increasing evidence of their roles in gene regulation. However, most of these studies have been performed in short single-stranded oligonucleotides, far from the intracellular environment. In cells, i-motif-forming sequences are flanked by DNA duplexes and packed in the genome. Therefore, exploring the conformational dynamics and kinetics of i-motif under such topologically constrained environments is highly relevant in predicting their biological roles. Using single-molecule fluorescence analysis of self-assembled DNA duplexes and nanocircles, we show that the topological environments play a key role on i-motif stability and dynamics. While the human telomere sequence (C3TAA)3C3 assumes i-motif structure at pH 5.5 regardless of topological constraint, it undergoes conformational dynamics among unfolded, partially folded and fully folded states at pH 6.5. The lifetimes of i-motif and the partially folded state at pH 6.5 were determined to be 6 ± 2 and 31 ± 11 s, respectively. Consistent with the partially folded state observed in fluorescence analysis, interrogation of current versus time traces obtained from nanopore analysis at pH 6.5 shows long-lived shallow blockades with a mean lifetime of 25 ± 6 s. Such lifetimes are sufficient for the i-motif and partially folded states to interact with proteins to modulate cellular processes.
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Affiliation(s)
- Anoja Megalathan
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Bobby D Cox
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Peter D Wilkerson
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Anisa Kaur
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Kumar Sapkota
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Joseph E Reiner
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Soma Dhakal
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
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17
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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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18
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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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19
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Luchian T, Park Y, Asandei A, Schiopu I, Mereuta L, Apetrei A. Nanoscale Probing of Informational Polymers with Nanopores. Applications to Amyloidogenic Fragments, Peptides, and DNA-PNA Hybrids. Acc Chem Res 2019; 52:267-276. [PMID: 30605305 DOI: 10.1021/acs.accounts.8b00565] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The decades long advances in nanotechnology, biomolecular sciences, and protein engineering ushered the introduction of groundbreaking technologies devoted to understanding how matter behaves at single particle level. Arguably, one of the simplest in concept is the nanopore-based paradigm, with deep roots in what is originally known as the Coulter counter, resistive-pulse technique. Historically, a nanopore system comprising the oligomeric protein generated by Staphylococcus aureus toxin α-hemolysin (α-HL) was first applied to detecting polynucleotides, as revealed in 1996 by John J. Kasianowicz, Eric Brandin, Daniel Branton, and David W. Deamer, in the Proceedings of the National Academy of Sciences. Nowadays, a wide variety of other solid-state or protein-based nanopores have emerged as efficient tools for stochastic sensing of analytes as small as single metal ions, handling single molecules, or real-time, label-free probing of chemical reactions at single-molecule level. In this Account, we demonstrate the usefulness of the α-HL nanopore on probing metal-induced folding of peptides, and to investigating the reversible binding of various metals to physiologically relevant amyloid fragments. The widely recognized Achilles heel of the approach, is the relatively short dwell time of the analytes inside the nanopore. This hinders the collection of sufficient data required to infer statistically meaningful conclusions about the physical or chemical state of the studied analyte. To mitigate this, various approaches were successfully applied in particular experiments, including but not restricted to altering physical parameters of the aqueous solution, downsizing the nanopore geometry, the controlled tuning of the balance between the electrostatic and electro-osmotic forces, coating nanopores with a fluid lipid bilayer, employing a pressure-voltage biased pore. From our perspective, in this Account, we will present two strategies aimed at controlling the analyte passage across the α-HL. First, we will reveal how the electroosmotic flow can be harnessed to control residence time, direction, and the sequence of spatiotemporal dynamics of a single peptide along the nanopore. This also allows one to identify the mesoscopic trajectory of a peptide exiting the nanopore through either the vestibule or β-barrel moiety. Second, we lay out the principles of an approach dubbed "nanopore tweezing", enabling simultaneous capture rate increase and escape rate decrease of a peptide from the α-HL, with the applied voltage. At its core, this method requires the creation of an electrical dipole on the peptide under study, via engineering positive and negative amino acid residues at the two ends of the peptide. Concise applications of this approach are being demonstrated, as in proof-of-concept experiments we probed the primary structure exploration of polypeptides, via discrimination between selected neutral amino acid residues. Another useful venue provided by the nanopores is represented by single-molecule force experiments on captured analytes inside the nanopore, which proved useful in exploring force-induced rupture of nucleic acids duplexes, hairpins, or various nucleic acids-ligand conjugates. We will show that when applied to oppositely charged, polypeptide-functionalized PNA-DNA duplexes, the nanopore tweezing introduces a new generation of force-spectroscopy nanopore-based platforms, facilitating unzipping of a captured duplex and enabling the duplex hybridization energy estimation.
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Affiliation(s)
- Tudor Luchian
- Department of Physics, ‘Alexandru I. Cuza’ University, Iasi, Romania 700506
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea 61452
| | - Alina Asandei
- Interdisciplinary Research Institute, Sciences Department, ‘Alexandru I. Cuza’ University, Iasi, Romania 700506
| | - Irina Schiopu
- Interdisciplinary Research Institute, Sciences Department, ‘Alexandru I. Cuza’ University, Iasi, Romania 700506
| | - Loredana Mereuta
- Department of Physics, ‘Alexandru I. Cuza’ University, Iasi, Romania 700506
| | - Aurelia Apetrei
- Department of Physics, ‘Alexandru I. Cuza’ University, Iasi, Romania 700506
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20
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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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21
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Tan CS, Fleming AM, Ren H, Burrows CJ, White HS. γ-Hemolysin Nanopore Is Sensitive to Guanine-to-Inosine Substitutions in Double-Stranded DNA at the Single-Molecule Level. J Am Chem Soc 2018; 140:14224-14234. [PMID: 30269492 DOI: 10.1021/jacs.8b08153] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Biological nanopores provide a unique single-molecule sensing platform to detect target molecules based on their specific electrical signatures. The γ-hemolysin (γ-HL) protein produced by Staphylococcus aureus is able to assemble into an octamer nanopore with a ∼2.3 nm diameter β-barrel. Herein, we demonstrate the first application of γ-HL nanopore for DNA structural analysis. To optimize conditions for ion-channel recording, the properties of the γ-HL pore (e.g., conductance, voltage-dependent gating, and ion-selectivity) were characterized at different pH, temperature, and electrolyte concentrations. The optimal condition for DNA analysis using γ-HL corresponds to 3 M KCl, pH 5, and T = 20 °C. The γ-HL protein nanopore is able to translocate dsDNA at about ∼20 bp/ms, and the unique current-signature of captured dsDNA can directly distinguish guanine-to-inosine substitutions at the single-molecule level with ∼99% accuracy. The slow dsDNA threading and translocation processes indicate this wild-type γ-HL channel has potential to detect other base modifications in dsDNA.
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Affiliation(s)
- Cherie S Tan
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Aaron M Fleming
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Hang Ren
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Henry S White
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 , United States
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22
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Shi X, Li Q, Gao R, Si W, Liu SC, Aksimentiev A, Long YT. Dynamics of a Molecular Plug Docked onto a Solid-State Nanopore. J Phys Chem Lett 2018; 9:4686-4694. [PMID: 30058336 PMCID: PMC6252057 DOI: 10.1021/acs.jpclett.8b01755] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Docking of a protein-DNA complex onto a nanopore can provide ample observation time, and has enabled collection of analytic applications of biological nanopores, including DNA sequencing. However, the application of the same principle to solid-state nanopores is tempered by poor understanding of the docking process. Here, we elucidate the behavior of individual protein-DNA complexes docked onto a solid-state nanopore by monitoring the nanopore ionic current. Repeat docking of monovalent streptavidin-DNA complexes is found to produce ionic current blockades that fluctuate between discrete levels. We elucidate the roles of the protein plug and the DNA tether in the docking process, finding the docking configurations to determine the multitude of the current blockade levels, whereas the frequency of the current level switching is determined by the interactions between the molecules and the solid-state membrane. Finally, we prove the feasibility of using the nanopore docking principle for single-molecule sensing using solid-state nanopores by detecting conformational changes of a tethered DNA molecule from a random coil to an i-motif state.
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Affiliation(s)
- Xin Shi
- Key Laboratory for Advanced Materials, School of Chemistry &Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China,
| | - Qiao Li
- Key Laboratory for Advanced Materials, School of Chemistry &Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China,
| | - Rui Gao
- Key Laboratory for Advanced Materials, School of Chemistry &Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China,
| | - Wei Si
- Department of Physics and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana–Champaign, 1110 W Green St, Urbana, IL 61801, USA
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - Shao-Chuang Liu
- Key Laboratory for Advanced Materials, School of Chemistry &Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China,
| | - Aleksei Aksimentiev
- Department of Physics and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana–Champaign, 1110 W Green St, Urbana, IL 61801, USA
| | - Yi-Tao Long
- Key Laboratory for Advanced Materials, School of Chemistry &Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China,
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23
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Ren W, Zheng K, Liao C, Yang J, Zhao J. Charge evolution during the unfolding of a single DNA i-motif. Phys Chem Chem Phys 2018; 20:916-924. [PMID: 29230450 DOI: 10.1039/c7cp06235d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The effective charge and evolution of single chains of a DNA i-motif during its unfolding process are investigated at the single molecule level. Using fluorescence correlation spectroscopy and photon counting histograms, the single chain dimensions and electrical potential of cytosine-rich human telomeric oligonucleotides are monitored, during their unfolding from the i-motif to the random coil state. It is discovered that the effective charge density of the DNA chain is very sensitive to conformation changes and the results remarkably expose the existence of an intermediate state of the unfolding process. A huge difference in pH value exists in the vicinity of the DNA chain and the bulk solution, depending on the salt concentration, as reflected by a down-shift in the pH value of unfolding. The presence of an external salt in the solution helps to stabilize the i-motif structure at low pH values due to the reduction of the effective charge density. It can also destabilize the folded structure in the pH range of the conformation transition due to the elevation of the local pH value, encouraging the deprotonation of the cytosine groups. These results provide new information for understanding the structure and stability of i-motif DNA, and its biological function, as well as the building blocks for smart nanomaterials.
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Affiliation(s)
- Weibin Ren
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
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24
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Jonchhe S, Shrestha P, Ascencio K, Mao H. A New Concentration Jump Strategy Reveals the Lifetime of i-Motif at Physiological pH without Force. Anal Chem 2018; 90:3205-3210. [DOI: 10.1021/acs.analchem.7b04661] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Sagun Jonchhe
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Prakash Shrestha
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Katia Ascencio
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Hanbin Mao
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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25
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Zhang X, Zhang D, Zhao C, Tian K, Shi R, Du X, Burcke AJ, Wang J, Chen SJ, Gu LQ. Nanopore electric snapshots of an RNA tertiary folding pathway. Nat Commun 2017; 8:1458. [PMID: 29133841 PMCID: PMC5684407 DOI: 10.1038/s41467-017-01588-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 09/29/2017] [Indexed: 12/22/2022] Open
Abstract
The chemical properties and biological mechanisms of RNAs are determined by their tertiary structures. Exploring the tertiary structure folding processes of RNA enables us to understand and control its biological functions. Here, we report a nanopore snapshot approach combined with coarse-grained molecular dynamics simulation and master equation analysis to elucidate the folding of an RNA pseudoknot structure. In this approach, single RNA molecules captured by the nanopore can freely fold from the unstructured state without constraint and can be programmed to terminate their folding process at different intermediates. By identifying the nanopore signatures and measuring their time-dependent populations, we can “visualize” a series of kinetically important intermediates, track the kinetics of their inter-conversions, and derive the RNA pseudoknot folding pathway. This approach can potentially be developed into a single-molecule toolbox to investigate the biophysical mechanisms of RNA folding and unfolding, its interactions with ligands, and its functions. While RNA folding is critical for its function, study of this process is challenging. Here, the authors combine nanopore single-molecule manipulation with theoretical analysis to follow the folding of an RNA pseudoknot, monitoring the intermediate states and the kinetics of their interconversion.
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Affiliation(s)
- Xinyue Zhang
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, 65211, USA
| | - Dong Zhang
- Department of Physics, University of Missouri, Columbia, MO, 65211, USA
| | - Chenhan Zhao
- Department of Physics, University of Missouri, Columbia, MO, 65211, USA
| | - Kai Tian
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, 65211, USA
| | - Ruicheng Shi
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA
| | - Xiao Du
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA
| | - Andrew J Burcke
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA
| | - Jing Wang
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA
| | - Shi-Jie Chen
- Department of Physics, University of Missouri, Columbia, MO, 65211, USA. .,Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA. .,Informatics Institute, University of Missouri, Columbia, MO, 65211, USA.
| | - Li-Qun Gu
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA. .,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, 65211, USA.
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26
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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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27
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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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28
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Zhang L, Zhang K, Rauf S, Dong D, Liu Y, Li J. Single-Molecule Analysis of Human Telomere Sequence Interactions with G-quadruplex Ligand. Anal Chem 2016; 88:4533-40. [DOI: 10.1021/acs.analchem.6b00555] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ling Zhang
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Kaixiang Zhang
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Sana Rauf
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Duo Dong
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Yang Liu
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
| | - Jinghong Li
- Department
of Chemistry,
Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China
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Ding Y, Kanavarioti A. Single pyrimidine discrimination during voltage-driven translocation of osmylated oligodeoxynucleotides via the α-hemolysin nanopore. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:91-101. [PMID: 26925357 PMCID: PMC4734350 DOI: 10.3762/bjnano.7.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/08/2016] [Indexed: 06/05/2023]
Abstract
The influence of an electric field on an isolated channel or nanopore separating two compartments filled with electrolytes produces a constant ion flux through the pore. Nucleic acids added to one compartment traverse the pore, and modulate the current in a sequence-dependent manner. While translocation is faster than detection, the α-hemolysin nanopore (α-HL) successfully senses base modifications in ssDNA immobilized within the pore. With the assistance of a processing enzyme to slow down translocation, nanopore-based DNA sequencing is now a commercially available platform. However, accurate base calling is challenging because α-HL senses a sequence, and not a single nucleotide. Osmylated DNA was recently proposed as a surrogate for nanopore-based sequencing. Osmylation is the addition of osmium tetroxide 2,2'-bipyridine (OsBp) to the C5-C6 pyrimidine double bond. The process is simple, selective for deoxythymidine (dT) over deoxycytidine (dC), unreactive towards the purines, practically 100% effective, and strikingly independent of length, sequence, and composition. Translocation of an oligodeoxynucleotide (oligo) dA10XdA9 via α-HL is relatively slow, and exhibits distinct duration as well as distinct residual current when X = dA, dT(OsBp), or dC(OsBp). The data indicate that the α-HL constriction zone/β-barrel interacts strongly with both OsBp and the base. A 23 nucleotide long oligo with four dT(OsBp) traverses 18-times slower, and the same oligo with nine (dT+dC)(OsBp) moieties traverses 84-times slower compared to dA20, suggesting an average rate of 40 or 180 μs/base, respectively. These translocation speeds are well above detection limits, may be further optimized, and clear the way for nanopore-based sequencing using osmylated DNA.
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Affiliation(s)
- Yun Ding
- Chemistry Department, University of Utah, Salt Lake City, UT, USA
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Galer P, Wang B, Šket P, Plavec J. Reversible pH Switch of Two-Quartet G-Quadruplexes Formed by Human Telomere. Angew Chem Int Ed Engl 2016; 55:1993-7. [PMID: 26836334 DOI: 10.1002/anie.201507569] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/04/2015] [Indexed: 12/30/2022]
Abstract
A four-repeat human telomere DNA sequence without the 3'-end guanine, d[TAGGG(TTAGGG)2 TTAGG] (htel1-ΔG23) has been found to adopt two distinct two G-quartet antiparallel basket-type G-quadruplexes, TD and KDH(+) in presence of KCl. NMR, CD, and UV spectroscopy have demonstrated that topology of KDH(+) form is distinctive with unique protonated T18⋅A20(+) ⋅G5 base triple and other capping structural elements that provide novel insight into structural polymorphism and heterogeneity of G-quadruplexes in general. Specific stacking interactions amongst two G-quartets flanking base triples and base pairs in TD and KDH(+) forms are reflected in 10 K higher thermal stability of KDH(+) . Populations of TD and KDH(+) forms are controlled by pH. The (de)protonation of A20 is the key for pH driven structural transformation of htel1-ΔG23. Reversibility offers possibilities for its utilization as a conformational switch within different compartments of living cell enabling specific ligand and protein interactions.
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Affiliation(s)
- Petra Galer
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Baifan Wang
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia. .,EN-FIST Center of Excellence, Trg OF 13, 1000, Ljubljana, Slovenia.
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia. .,EN-FIST Center of Excellence, Trg OF 13, 1000, Ljubljana, Slovenia. .,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia.
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Galer P, Wang B, Šket P, Plavec J. Reversible pH Switch of Two-Quartet G-Quadruplexes Formed by Human Telomere. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201507569] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Petra Galer
- Slovenian NMR Center; National Institute of Chemistry; Hajdrihova 19 Ljubljana Slovenia
| | - Baifan Wang
- Slovenian NMR Center; National Institute of Chemistry; Hajdrihova 19 Ljubljana Slovenia
| | - Primož Šket
- Slovenian NMR Center; National Institute of Chemistry; Hajdrihova 19 Ljubljana Slovenia
- EN-FIST Center of Excellence; Trg OF 13 1000 Ljubljana Slovenia
| | - Janez Plavec
- Slovenian NMR Center; National Institute of Chemistry; Hajdrihova 19 Ljubljana Slovenia
- EN-FIST Center of Excellence; Trg OF 13 1000 Ljubljana Slovenia
- Faculty of Chemistry and Chemical Technology; University of Ljubljana; Večna pot 113 Ljubljana Slovenia
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Ding Y, Fleming AM, White HS, Burrows CJ. Differentiation of G:C vs A:T and G:C vs G:mC Base Pairs in the Latch Zone of α-Hemolysin. ACS NANO 2015; 9:11325-32. [PMID: 26506108 PMCID: PMC4876701 DOI: 10.1021/acsnano.5b05055] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The α-hemolysin (α-HL) nanopore can detect DNA strands under an electrophoretic force via many regions of the channel. Our laboratories previously demonstrated that trapping duplex DNA in the vestibule of wild-type α-HL under force could distinguish the presence of an abasic site compared to a G:C base pair positioned in the latch zone at the top of the vestibule. Herein, a series of duplexes were probed in the latch zone to establish if this region can detect more subtle features of base pairs beyond the complete absence of a base. The results of these studies demonstrate that the most sensitive region of the latch can readily discriminate duplexes in which one G:C base pair is replaced by an A:T. Additional experiments determined that while neither 8-oxo-7,8-dihydroguanine nor 7-deazaguanine opposite C could be differentiated from a G:C base pair, in contrast, the epigenetic marker 5-methylcytosine, when present in both strands of the duplex, yielded new blocking currents when compared to strands with unmodified cytosine. The results are discussed with respect to experimental design for utilization of the latch zone of α-HL to probe specific regions of genomic samples.
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Affiliation(s)
| | | | - Henry S. White
- To whom correspondence should be addressed: Telephone: (801) 585-7290 or (801) 585-6256, or
| | - Cynthia J. Burrows
- To whom correspondence should be addressed: Telephone: (801) 585-7290 or (801) 585-6256, or
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