1
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Montserrat Pagès A, Hertog M, Nicolaï B, Spasic D, Lammertyn J. Unraveling the Kinetics of the 10-23 RNA-Cleaving DNAzyme. Int J Mol Sci 2023; 24:13686. [PMID: 37761982 PMCID: PMC10531344 DOI: 10.3390/ijms241813686] [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: 06/12/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
DNA-based enzymes, or DNAzymes, are single-stranded DNA sequences with the ability to catalyze various chemical reactions, including the cleavage of the bond between two RNA nucleotides. Lately, an increasing interest has been observed in these RNA-cleaving DNAzymes in the biosensing and therapeutic fields for signal generation and the modulation of gene expression, respectively. Additionally, multiple efforts have been made to study the effects of the reaction environment and the sequence of the catalytic core on the conversion of the substrate into product. However, most of these studies have only reported alterations of the general reaction course, but only a few have focused on how each individual reaction step is affected. In this work, we present for the first time a mathematical model that describes and predicts the reaction of the 10-23 RNA-cleaving DNAzyme. Furthermore, the model has been employed to study the effect of temperature, magnesium cations and shorter substrate-binding arms of the DNAzyme on the different kinetic rate constants, broadening the range of conditions in which the model can be exploited. In conclusion, this work depicts the prospects of such mathematical models to study and anticipate the course of a reaction given a particular environment.
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Affiliation(s)
- Aida Montserrat Pagès
- Department of Biosystems, Biosensors Group, KU Leuven—University of Leuven, 3001 Leuven, Belgium
| | - Maarten Hertog
- Department of Biosystems, Postharvest Group, KU Leuven—University of Leuven, 3001 Leuven, Belgium
| | - Bart Nicolaï
- Department of Biosystems, Postharvest Group, KU Leuven—University of Leuven, 3001 Leuven, Belgium
| | - Dragana Spasic
- Department of Biosystems, Biosensors Group, KU Leuven—University of Leuven, 3001 Leuven, Belgium
| | - Jeroen Lammertyn
- Department of Biosystems, Biosensors Group, KU Leuven—University of Leuven, 3001 Leuven, Belgium
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2
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Choosing the Probe for Single-Molecule Fluorescence Microscopy. Int J Mol Sci 2022; 23:ijms232314949. [PMID: 36499276 PMCID: PMC9735909 DOI: 10.3390/ijms232314949] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/18/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Probe choice in single-molecule microscopy requires deeper evaluations than those adopted for less sensitive fluorescence microscopy studies. Indeed, fluorophore characteristics can alter or hide subtle phenomena observable at the single-molecule level, wasting the potential of the sophisticated instrumentation and algorithms developed for advanced single-molecule applications. There are different reasons for this, linked, e.g., to fluorophore aspecific interactions, brightness, photostability, blinking, and emission and excitation spectra. In particular, these spectra and the excitation source are interdependent, and the latter affects the autofluorescence of sample substrate, medium, and/or biological specimen. Here, we review these and other critical points for fluorophore selection in single-molecule microscopy. We also describe the possible kinds of fluorophores and the microscopy techniques based on single-molecule fluorescence. We explain the importance and impact of the various issues in fluorophore choice, and discuss how this can become more effective and decisive for increasingly demanding experiments in single- and multiple-color applications.
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3
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Jung J, Kim SY, Kim SK. Single-molecule study of the effects of temperature, pH, and RNA base on the stepwise enzyme kinetics of 10–23 deoxyribozyme. RSC Adv 2022; 12:14883-14887. [PMID: 35702195 PMCID: PMC9113834 DOI: 10.1039/d2ra02131e] [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: 04/02/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022] Open
Abstract
We investigated how the stepwise enzyme kinetics of 10–23 deoxyribozyme was affected by temperature, pH, and RNA residue of the substrate at the single-molecule level. A deoxyribozyme-substrate system was employed to temporally categorize a single-turnover reaction into four distinct steps: binding, cleavage, dissociation of one of the cleaved fragments, and dissociation of the other fragment. The dwell time of each step was measured as the temperature was varied from 26 to 34 °C, to which the transition state theory was applied to obtain the enthalpy and entropy of activation for individual steps. In addition, we found that only the cleavage step was significantly affected by pH, indicating that it involves deprotonation of a single proton. We also found that different RNA residues specifically affect the cleavage step and cause the dwell time to change by as much as 5 times. We investigated how the stepwise enzyme kinetics of 10–23 deoxyribozyme was affected by temperature, pH, and RNA residue of the substrate at the single-molecule level.![]()
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Affiliation(s)
- Jiwon Jung
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Seon Yong Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
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4
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Characterization of a DNA-hydrolyzing DNAzyme for generation of PCR strands of unequal length. Biochimie 2020; 179:181-189. [PMID: 33022314 DOI: 10.1016/j.biochi.2020.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/13/2020] [Accepted: 10/01/2020] [Indexed: 11/21/2022]
Abstract
I-R3 DNAzyme is a small, highly active catalytic DNA for DNA hydrolysis. In here, we designed two cis-structure DNAzymes (I-R3N and I-R3S) based on the different locates of the joint linker between I-R3 and its substrate. Data demonstrated that both DNAzymes were highly dependent on Zn2+, and worked at a narrow range around pH 7.0. They exhibited strong anti-interference with Mg2+ and Ca2+, but inhibited by Na+ and K+. Moreover, single and multiple-site mutations were generated within the catalytic core to carry out a comprehensive mutational study of I-R3 motif, in which most nucleotides were highly conserved and the nucleotides A5, T11 and T8 were identified as the mutational hotspots. Furthermore, an efficient variant A5G was obtained and its reaction condition was optimized. Finally, we constructed A5G to the 3' end of a single-stranded DNA (ssDNA) and applied it for asymmetrical PCR amplification to produce a single and double-stranded DNA mixture, in which A5G within ssDNA can self-cleave to generate a shorter desired ssDNA by denaturing gel separation. This would provide a new non-chemical modification approach for preparation of the expected ssDNA for in vitro selection of DNAzymes.
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5
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He Y, Zhou Y, Chen D, Liu J. Global Folding of a Na
+
‐Specific DNAzyme Studied by FRET. Chembiochem 2018; 20:385-393. [DOI: 10.1002/cbic.201800548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Yanping He
- State Key Laboratory of Precision Measurement Technology and InstrumentsUniversity of Tianjin Tianjin 300072 P.R. China
- Department of Chemistry, Waterloo Institute for NanotechnologyUniversity of Waterloo Waterloo Ontario N2L 3G1 Canada
| | - Yibo Zhou
- School of Chemistry and Biological EngineeringChangsha University of Science and Technology Changsha 410114 P.R. China
| | - Da Chen
- State Key Laboratory of Precision Measurement Technology and InstrumentsUniversity of Tianjin Tianjin 300072 P.R. China
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for NanotechnologyUniversity of Waterloo Waterloo Ontario N2L 3G1 Canada
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6
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Li Z, Zhu J, He J. Conformational studies of 10-23 DNAzyme in solution through pyrenyl-labeled 2'-deoxyadenosine derivatives. Org Biomol Chem 2018; 14:9846-9858. [PMID: 27714317 DOI: 10.1039/c6ob01702a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
10-23 DNAzyme is a small catalytic DNA molecule. Studies on its conformation in solution are critical for understanding its catalytic mechanism and functional optimization. Based on our previous research, two fluorescent nucleoside analogues 1 and 2 were designed for the introduction of a pyrenyl group at one of the five dA residues in the catalytic core and the unpaired adenosine residue in its full-DNA substrate, respectively. Ten pyrenyl-pyrenyl pairs are formed in the DNAzyme-substrate complexes in solution for sensing the spacial positions of the five dA residues relative to the cleavage site using fluorescence spectra. The position-dependent quenching effect of pyrene emission fluorescence by nucleobases, especially the pyrenyl-pyrenyl interaction, was observed for some positions. The adenine residues in the 3'-part of the catalytic loop seem to be closer to the cleavage site than the adenine residues in the 5'-part, which is consistent with the molecular dynamics simulation result. The catalytic activities and Tm changes also confirmed the effect of the pyrenyl-nucleobase and pyrenyl-pyrenyl pair interactions. Together with functional group mutations, catalytically relevant nucleobases will be identified for understanding the catalytic mechanism of 10-23 DNAzyme.
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Affiliation(s)
- Zhiwen Li
- College of Life Science, Guizhou University, Guiyang 550025, China
| | - Junfei Zhu
- College of Life Science, Guizhou University, Guiyang 550025, China
| | - Junlin He
- Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
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7
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Lee JY, Lake RJ, Kirk J, Bohr VA, Fan HY, Hohng S. NAP1L1 accelerates activation and decreases pausing to enhance nucleosome remodeling by CSB. Nucleic Acids Res 2017; 45:4696-4707. [PMID: 28369616 PMCID: PMC5416873 DOI: 10.1093/nar/gkx188] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 03/16/2017] [Indexed: 11/22/2022] Open
Abstract
Cockayne syndrome protein B (CSB) belongs to the SWI2/SNF2 ATP-dependent chromatin remodeler family, and CSB is the only ATP-dependent chromatin remodeler essential for transcription-coupled nucleotide excision DNA repair. CSB alone remodels nucleosomes ∼10-fold slower than the ACF remodeling complex. Strikingly, NAP1-like histone chaperones interact with CSB and greatly enhance CSB-mediated chromatin remodeling. While chromatin remodeling by CSB and NAP1-like proteins is crucial for efficient transcription-coupled DNA repair, the mechanism by which NAP1-like proteins enhance chromatin remodeling by CSB remains unknown. Here we studied CSB's DNA-binding and nucleosome-remodeling activities at the single molecule level in real time. We also determined how the NAP1L1 chaperone modulates these activities. We found that CSB interacts with DNA in two principle ways: by simple binding and a more complex association that involves gross DNA distortion. Remarkably, NAP1L1 suppresses both these interactions. Additionally, we demonstrate that nucleosome remodeling by CSB consists of three distinct phases: activation, translocation and pausing, similar to ACF. Importantly, we found that NAP1L1 promotes CSB-mediated remodeling by accelerating both activation and translocation. Additionally, NAP1L1 increases CSB processivity by decreasing the pausing probability during translocation. Our study, therefore, uncovers the different steps of CSB-mediated chromatin remodeling that can be regulated by NAP1L1.
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Affiliation(s)
- Ju Yeon Lee
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea.,Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea.,National Center of Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea
| | - Robert J Lake
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jaewon Kirk
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea.,Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea.,National Center of Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Hua-Ying Fan
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sungchul Hohng
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea.,Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea.,National Center of Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea
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8
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Folding of the silver aptamer in a DNAzyme probed by 2-aminopurine fluorescence. Biochimie 2017; 145:145-150. [PMID: 28711684 DOI: 10.1016/j.biochi.2017.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 07/04/2017] [Indexed: 12/28/2022]
Abstract
The RNA-cleaving Ag10c DNAzyme was recently isolated via in vitro selection and it can bind two Ag+ ions for activity. The Ag10c contains a well-defined Ag+ binding aptamer as indicated by DMS footprinting. Since aptamer binding is often accompanied with conformational changes, we herein used 2-aminopurine (2AP) to probe its folding in the presence of Ag+. The Ag10c was respectively labeled with 2AP at three different positions, both in the substrate strand and in the enzyme strand, one at a time. Ag+-induced folding was observed at the substrate cleavage junction and the A9 position of the enzyme strand, consistent with aptamer binding. The measured Kd at the A9 position was 18 μM Ag+ with a Hill coefficient of 2.17, similar to those obtained from the previous cleavage activity based assays. However, labeling a 2AP at the A2 position inhibited the activity and folding. Compared to other metal ions, Ag+ has a unique sigmoidal folding profile indicative of multiple silver binding cooperatively. This suggests that Ag+ can induce a local folding in the enzyme loop and this folding is important for activity. This study provides important biophysical insights into this new DNAzyme, suggesting the possibility of designing folding-based biosensors for Ag+.
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9
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Zhou W, Ding J, Liu J. A highly specific sodium aptamer probed by 2-aminopurine for robust Na+ sensing. Nucleic Acids Res 2016; 44:10377-10385. [PMID: 27655630 PMCID: PMC5137442 DOI: 10.1093/nar/gkw845] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/10/2016] [Accepted: 09/13/2016] [Indexed: 12/12/2022] Open
Abstract
Sodium is one of the most abundant metals in the environment and in biology, playing critical ecological and physiological roles. Na+ is also the most common buffer salt for nucleic acids research, while its specific interaction with DNA has yet to be fully studied. Herein, we probe a highly selective and robust Na+ aptamer using 2-aminopurine (2AP), a fluorescent adenine analog. This aptamer has two DNA strands derived from the Ce13d DNAzyme. By introducing a 2AP at the cleavage site of the substrate strand, Na+ induces ∼40% fluorescence increase. The signaling is improved by a series of rational mutations, reaching >600% with the C10A20 double mutant. This fluorescence enhancement suggests relaxed base stacking near the 2AP label upon Na+ binding. By replacing a non-conserved adenine in the enzyme strand by 2AP, Na+-dependent fluorescence quenching is observed, suggesting that the enzyme loop folds into a more compact structure upon Na+ binding. The fluorescence changes allow for Na+ detection. With an optimized sequence, a detection limit of 0.4 mM Na+ is achieved, reaching saturated signal in less than 10 s. The sensor response is insensitive to ionic strength, which is critical for Na+ detection.
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Affiliation(s)
- Wenhu Zhou
- School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410013, China.,Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Jinsong Ding
- School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Juewen Liu
- School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410013, China .,Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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10
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Lerner E, Ploetz E, Hohlbein J, Cordes T, Weiss S. A Quantitative Theoretical Framework For Protein-Induced Fluorescence Enhancement-Förster-Type Resonance Energy Transfer (PIFE-FRET). J Phys Chem B 2016; 120:6401-10. [PMID: 27184889 PMCID: PMC4939467 DOI: 10.1021/acs.jpcb.6b03692] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
![]()
Single-molecule,
protein-induced fluorescence enhancement (PIFE)
serves as a molecular ruler at molecular distances inaccessible to
other spectroscopic rulers such as Förster-type resonance energy
transfer (FRET) or photoinduced electron transfer. In order to provide
two simultaneous measurements of two distances on different molecular
length scales for the analysis of macromolecular complexes, we and
others recently combined measurements of PIFE and FRET (PIFE-FRET)
on the single molecule level. PIFE relies on steric hindrance of the
fluorophore Cy3, which is covalently attached to a biomolecule of
interest, to rotate out of an excited-state trans isomer to the cis isomer through a 90° intermediate.
In this work, we provide a theoretical framework that accounts for
relevant photophysical and kinetic parameters of PIFE-FRET, show how
this framework allows the extraction of the fold-decrease in isomerization
mobility from experimental data, and show how these results provide
information on changes in the accessible volume of Cy3. The utility
of this model is then demonstrated for experimental results on PIFE-FRET
measurement of different protein–DNA interactions. The proposed
model and extracted parameters could serve as a benchmark to allow
quantitative comparison of PIFE effects in different biological systems.
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Affiliation(s)
- Eitan Lerner
- Department of Chemistry and Biochemistry, University of California Los Angeles , 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
| | - Evelyn Ploetz
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University and Research , Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.,Microspectroscopy Centre, Wageningen University and Research , Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, University of California Los Angeles , 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
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11
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Yang X, Xiao Z, Zhu J, Li Z, He J, Zhang L, Yang Z. Spatial conservation studies of nucleobases in 10–23 DNAzyme by 2′-positioned isonucleotides and enantiomers for increased activity. Org Biomol Chem 2016; 14:4032-8. [DOI: 10.1039/c6ob00390g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
d-/l-Isonucleotides were used to modify the catalytic core and recognition arms of 10–23 DNAzyme and prominently improved its bioactivity.
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Affiliation(s)
- Xiantao Yang
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing
- China
| | - Zhangping Xiao
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing
- China
| | - Junfei Zhu
- College of Life Sciences
- Guizhou University
- Guiyang 550025
- China
| | - Zhiwen Li
- College of Life Sciences
- Guizhou University
- Guiyang 550025
- China
| | - Junlin He
- Beijing Institute of Pharmacology and Toxicology
- Beijing 100850
- China
| | - Lihe Zhang
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing
- China
| | - Zhenjun Yang
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing
- China
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12
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Hollenstein M. DNA Catalysis: The Chemical Repertoire of DNAzymes. Molecules 2015; 20:20777-804. [PMID: 26610449 PMCID: PMC6332124 DOI: 10.3390/molecules201119730] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 12/24/2022] Open
Abstract
Deoxyribozymes or DNAzymes are single-stranded catalytic DNA molecules that are obtained by combinatorial in vitro selection methods. Initially conceived to function as gene silencing agents, the scope of DNAzymes has rapidly expanded into diverse fields, including biosensing, diagnostics, logic gate operations, and the development of novel synthetic and biological tools. In this review, an overview of all the different chemical reactions catalyzed by DNAzymes is given with an emphasis on RNA cleavage and the use of non-nucleosidic substrates. The use of modified nucleoside triphosphates (dN*TPs) to expand the chemical space to be explored in selection experiments and ultimately to generate DNAzymes with an expanded chemical repertoire is also highlighted.
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Affiliation(s)
- Marcel Hollenstein
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
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13
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Brown MS, Bennett T, Coker JA. Niche Genetic Algorithms are better than traditional Genetic Algorithms for de novo Protein Folding. F1000Res 2014. [DOI: 10.12688/f1000research.5412.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here we demonstrate that Niche Genetic Algorithms (NGA) are better at computing de novo protein folding than traditional Genetic Algorithms (GA). Previous research has shown that proteins can fold into their active forms in a limited number of ways; however, predicting how a set of amino acids will fold starting from the primary structure is still a mystery. GAs have a unique ability to solve these types of scientific problems because of their computational efficiency. Unfortunately, GAs are generally quite poor at solving problems with multiple optima. However, there is a special group of GAs called Niche Genetic Algorithms (NGA) that are quite good at solving problems with multiple optima. In this study, we use a specific NGA: the Dynamic-radius Species-conserving Genetic Algorithm (DSGA), and show that DSGA is very adept at predicting the folded state of proteins, and that DSGA is better than a traditional GA in deriving the correct folding pattern of a protein.
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14
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Hohng S, Lee S, Lee J, Jo MH. Maximizing information content of single-molecule FRET experiments: multi-color FRET and FRET combined with force or torque. Chem Soc Rev 2014; 43:1007-13. [PMID: 23970315 DOI: 10.1039/c3cs60184f] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Since its first demonstration about twenty years ago, single-molecule fluorescence resonance energy transfer (FRET) has undergone remarkable technical advances. In this tutorial review, we will discuss two technical advances that increase the information content of the single-molecule FRET measurements: single-molecule multi-color FRET and single-molecule FRET combined with force or torque. Our expectations for future developments will be briefly discussed at the end.
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Affiliation(s)
- Sungchul Hohng
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
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15
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Juette MF, Terry DS, Wasserman MR, Zhou Z, Altman RB, Zheng Q, Blanchard SC. The bright future of single-molecule fluorescence imaging. Curr Opin Chem Biol 2014; 20:103-11. [PMID: 24956235 DOI: 10.1016/j.cbpa.2014.05.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 05/09/2014] [Indexed: 11/13/2022]
Abstract
Single-molecule Förster resonance energy transfer (smFRET) is an essential and maturing tool to probe biomolecular interactions and conformational dynamics in vitro and, increasingly, in living cells. Multi-color smFRET enables the correlation of multiple such events and the precise dissection of their order and timing. However, the requirements for good spectral separation, high time resolution, and extended observation times place extraordinary demands on the fluorescent labels used in such experiments. Together with advanced experimental designs and data analysis, the development of long-lasting, non-fluctuating fluorophores is therefore proving key to progress in the field. Recently developed strategies for obtaining ultra-stable organic fluorophores spanning the visible spectrum are underway that will enable multi-color smFRET studies to deliver on their promise of previously unachievable biological insights.
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Affiliation(s)
- Manuel F Juette
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Daniel S Terry
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Michael R Wasserman
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Zhou Zhou
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Roger B Altman
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Qinsi Zheng
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States; Tri-Institutional Training Program in Chemical Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States; Tri-Institutional Training Program in Chemical Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, United States.
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16
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Abstract
Increasing interest in detecting metal ions in many chemical and biomedical fields has created demands for developing sensors and imaging agents for metal ions with high sensitivity and selectivity. This review covers recent progress in DNA-based sensors and imaging agents for metal ions. Through both combinatorial selection and rational design, a number of metal-ion-dependent DNAzymes and metal-ion-binding DNA structures that can selectively recognize specific metal ions have been obtained. By attachment of these DNA molecules with signal reporters such as fluorophores, chromophores, electrochemical tags, and Raman tags, a number of DNA-based sensors for both diamagnetic and paramagnetic metal ions have been developed for fluorescent, colorimetric, electrochemical, and surface Raman detection. These sensors are highly sensitive (with a detection limit down to 11 ppt) and selective (with selectivity up to millions-fold) toward specific metal ions. In addition, through further development to simplify the operation, such as the use of "dipstick tests", portable fluorometers, computer-readable disks, and widely available glucose meters, these sensors have been applied for on-site and real-time environmental monitoring and point-of-care medical diagnostics. The use of these sensors for in situ cellular imaging has also been reported. The generality of the combinatorial selection to obtain DNAzymes for almost any metal ion in any oxidation state and the ease of modification of the DNA with different signal reporters make DNA an emerging and promising class of molecules for metal-ion sensing and imaging in many fields of applications.
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Affiliation(s)
- Yu Xiang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Fax: 217-244-3186; Tel: 217-333-2619
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Fax: 217-244-3186; Tel: 217-333-2619
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RUEDAS-RAMA MJ, ALVAREZ-PEZ JM, ORTE A. SOLVING SINGLE BIOMOLECULES BY ADVANCED FRET-BASED SINGLE-MOLECULE FLUORESCENCE TECHNIQUES. ACTA ACUST UNITED AC 2014. [DOI: 10.1142/s1793048013300041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The use of Förster resonance energy transfer (FRET) has undergone a renaissance in the last two decades, especially in the study of structure of biomolecules, biomolecular interactions, and dynamics. Thanks to powerful advances in single-molecule fluorescence (SMF) techniques, seeing molecules at work is a reality, which has helped to build up the mindset of molecular machines. In the last few years, many technical developments have broadened the applications of SMF-FRET, expanding the amount of information that can be recovered from individual molecules. Here, we focus on the non-standard SMF-FRET techniques, such as two-color coincidence detection (TCCD), alternating laser excitation (ALEX), multiparameter fluorescence detection (MFD); the addition of fluorescence lifetime as an orthogonal dimension in single-molecule experiments; or the development of novel and improved methods of analysis constituting to a set of advanced methodologies that may become routine tools in a close future. [Formula: see text]Special Issue Comment: This review about advanced single-molecule FRET techniques is specially related to the review by Jørgensen and Hatzakis,6 who detail experimetal strategies to solve the activity of single enzymes. The advanced techniques described in our paper may serve as interesting alternatives when applied to enzyme studies. Our manuscript is also related to the reviews in this Special Issue that deal with model solving.22,130
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Affiliation(s)
- M. J. RUEDAS-RAMA
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Cartuja Campus, Granada, 18071, Spain
| | - J. M. ALVAREZ-PEZ
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Cartuja Campus, Granada, 18071, Spain
| | - A. ORTE
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Cartuja Campus, Granada, 18071, Spain
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Milles S, Lemke EA. What precision-protein-tuning and nano-resolved single molecule sciences can do for each other. Bioessays 2012; 35:65-74. [DOI: 10.1002/bies.201200094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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