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Ziemkiewicz K, Warminski M, Wojcik R, Kowalska J, Jemielity J. Quick Access to Nucleobase-Modified Phosphoramidites for the Synthesis of Oligoribonucleotides Containing Post-Transcriptional Modifications and Epitranscriptomic Marks. J Org Chem 2022; 87:10333-10348. [PMID: 35857285 PMCID: PMC9361293 DOI: 10.1021/acs.joc.2c01390] [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] [Indexed: 11/30/2022]
Abstract
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Herein, we report a straightforward one-step procedure
for modifying N-nucleophilic groups in the nucleobases
of commercially
available nucleoside phosphoramidites. This method involves the deprotonation
of amide groups under phase-transfer conditions and subsequent reaction
with electrophilic molecules such as alkyl halides or organic isocyanates.
Using this approach, we obtained 10 different classes of modified
nucleoside phosphoramidites suitable for the synthesis of oligonucleotides,
including several noncanonical nucleotides found in natural RNA or
DNA (e.g., m6A, i6A, m1A, g6A, m3C, m4C, m3U, m1G,
and m2G). Such modification of nucleobases is a common
mechanism for post-transcriptional regulation of RNA stability and
translational activity in various organisms. To better understand
this process, relevant cellular recognition partners (e.g., proteins)
must be identified and characterized. However, this step has been
impeded by limited access to molecular tools containing such modified
nucleotides.
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Affiliation(s)
- Kamil Ziemkiewicz
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland
| | - Marcin Warminski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw 02-093, Poland
| | - Radoslaw Wojcik
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw 02-093, Poland
| | - Jacek Jemielity
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland
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2
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Li Y, Liu J. Aptamer-based strategies for recognizing adenine, adenosine, ATP and related compounds. Analyst 2021; 145:6753-6768. [PMID: 32909556 DOI: 10.1039/d0an00886a] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Adenine is a key nucleobase, adenosine is an endogenous regulator of the immune system, while adenosine triphosphate (ATP) is the energy source of many biological reactions. Selective detection of these molecules is useful for understanding biological processes, biochemical reactions and signaling. Since 1993, various aptamers have been reported to bind to adenine and its derivatives. In addition, the adenine riboswitch was later discovered. This review summarizes the efforts for the selection of RNA and DNA aptamers for adenine derivatives, and we pay particular attention to the specificity of binding. In addition, other molecular recognition strategies based on rational sequence design are also introduced. Most of the work in the field was performed on the classic DNA aptamer for adenosine and ATP reported by the Szostak group. Based on this aptamer, some representative applications such as the design of fluorescent, colorimetric and electrochemical biosensors, intracellular imaging, and ATP-responsive materials are also described. In addition, we critically review the limit of the reported aptamers and also important problems in the field, which can give future research opportunities.
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Affiliation(s)
- Yuqing Li
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
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3
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Yokobayashi Y. High-Throughput Analysis and Engineering of Ribozymes and Deoxyribozymes by Sequencing. Acc Chem Res 2020; 53:2903-2912. [PMID: 33164502 DOI: 10.1021/acs.accounts.0c00546] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ribozymes and deoxyribozymes are catalytic RNA and DNA, respectively, that catalyze chemical reactions such as self-cleavage or ligation reactions. While some ribozymes are found in nature, a larger variety of ribozymes and deoxyribozymes have been discovered by in vitro selection from random sequences. These catalytic nucleic acids, especially ribozymes, are of fundamental interest because they are crucial for the RNA world hypothesis, which suggests that RNA played a central role in both the propagation of genetic information and catalyzing metabolic reactions in primordial life prior to the emergence of proteins and DNA. On the practical side, catalytic nucleic acids have been extensively engineered for various applications, such as biosensors and genetic devices for synthetic biology. Therefore, it is important to gain a deeper understanding of the sequence-function relationships of ribozymes and deoxyribozymes.Mutational analysis, or measurements of activities of catalytic nucleic acid mutants, is one of the most fundamental approaches for that purpose. Mutations that abolish, reduce, retain, or even increase activity provide useful information about nucleic acid catalysts for engineering and other purposes. However, methods for mutational analysis of ribozymes and deoxyribozymes have not evolved much for decades, requiring tedious and low-throughput assays (e.g., gel electrophoresis) of individually prepared mutants. This has prevented researchers from performing quantitative mutational analysis of ribozymes and deoxyribozymes on a large scale.To address this limitation, we developed a massively parallel ribozyme and deoxyribozyme assay strategy that allows >104 assays using high-throughput sequencing (HTS). We used HTS to literally count the number of cleaved (or ligated) and uncleaved (or unligated) ribozyme (or deoxyribozyme) sequences and calculated the activities of each mutant in a reaction mixture. This simple yet powerful strategy was applied to analyze the mutational effects of various natural and synthetic ribozymes and deoxyribozymes at scales impossible for conventional mutational analysis. These large-scale sequence-function data sets were used to better understand the functional consequences of mutations and to engineer ribozymes for practical applications. Furthermore, these newly available data are motivating researchers to employ more rigorous computational methods to extract additional insights such as structural information and nonlinear effects of multiple mutations. The new HTS-based assay strategy is distinct from and complementary to a related strategy that uses HTS to analyze ribozyme and deoxyribozyme populations subjected to in vitro selection. Postselection sequencing can cover a larger sequence space, although it does not directly quantify the activities of ribozyme and deoxyribozyme mutants. With further advances in DNA sequencing technologies and computational methods, there should be more opportunities to harness the power of HTS to deepen our understanding of catalytic nucleic acids and enhance our ability to engineer them for even more applications.
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Affiliation(s)
- Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
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4
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Scheitl CPM, Ghaem Maghami M, Lenz AK, Höbartner C. Site-specific RNA methylation by a methyltransferase ribozyme. Nature 2020; 587:663-667. [PMID: 33116304 PMCID: PMC7116789 DOI: 10.1038/s41586-020-2854-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/27/2020] [Indexed: 12/21/2022]
Abstract
Nearly all classes of coding and non-coding RNA undergo post-transcriptional modification, including RNA methylation. Methylated nucleotides are among the evolutionarily most-conserved features of transfer (t)RNA and ribosomal (r)RNA1,2. Many contemporary methyltransferases use the universal cofactor S-adenosylmethionine (SAM) as a methyl-group donor. SAM and other nucleotide-derived cofactors are considered to be evolutionary leftovers from an RNA world, in which ribozymes may have catalysed essential metabolic reactions beyond self-replication3. Chemically diverse ribozymes seem to have been lost in nature, but may be reconstructed in the laboratory by in vitro selection. Here we report a methyltransferase ribozyme that catalyses the site-specific installation of 1-methyladenosine in a substrate RNA, using O6-methylguanine as a small-molecule cofactor. The ribozyme shows a broad RNA-sequence scope, as exemplified by site-specific adenosine methylation in various RNAs. This finding provides fundamental insights into the catalytic abilities of RNA, serves a synthetic tool to install 1-methyladenosine in RNA and may pave the way to in vitro evolution of other methyltransferase and demethylase ribozymes.
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Affiliation(s)
- Carolin P M Scheitl
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Mohammad Ghaem Maghami
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Ann-Kathrin Lenz
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Claudia Höbartner
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
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5
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Micura R, Höbartner C. Fundamental studies of functional nucleic acids: aptamers, riboswitches, ribozymes and DNAzymes. Chem Soc Rev 2020; 49:7331-7353. [PMID: 32944725 DOI: 10.1039/d0cs00617c] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review aims at juxtaposing common versus distinct structural and functional strategies that are applied by aptamers, riboswitches, and ribozymes/DNAzymes. Focusing on recently discovered systems, we begin our analysis with small-molecule binding aptamers, with emphasis on in vitro-selected fluorogenic RNA aptamers and their different modes of ligand binding and fluorescence activation. Fundamental insights are much needed to advance RNA imaging probes for detection of exo- and endogenous RNA and for RNA process tracking. Secondly, we discuss the latest gene expression-regulating mRNA riboswitches that respond to the alarmone ppGpp, to PRPP, to NAD+, to adenosine and cytidine diphosphates, and to precursors of thiamine biosynthesis (HMP-PP), and we outline new subclasses of SAM and tetrahydrofolate-binding RNA regulators. Many riboswitches bind protein enzyme cofactors that, in principle, can catalyse a chemical reaction. For RNA, however, only one system (glmS ribozyme) has been identified in Nature thus far that utilizes a small molecule - glucosamine-6-phosphate - to participate directly in reaction catalysis (phosphodiester cleavage). We wonder why that is the case and what is to be done to reveal such likely existing cellular activities that could be more diverse than currently imagined. Thirdly, this brings us to the four latest small nucleolytic ribozymes termed twister, twister-sister, pistol, and hatchet as well as to in vitro selected DNA and RNA enzymes that promote new chemistry, mainly by exploiting their ability for RNA labelling and nucleoside modification recognition. Enormous progress in understanding the strategies of nucleic acids catalysts has been made by providing thorough structural fundaments (e.g. first structure of a DNAzyme, structures of ribozyme transition state mimics) in combination with functional assays and atomic mutagenesis.
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Affiliation(s)
- Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University Innsbruck, Innsbruck, Austria.
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6
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Scheitl CPM, Lange S, Höbartner C. New Deoxyribozymes for the Native Ligation of RNA. Molecules 2020; 25:molecules25163650. [PMID: 32796587 PMCID: PMC7465978 DOI: 10.3390/molecules25163650] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022] Open
Abstract
Deoxyribozymes (DNAzymes) are small, synthetic, single-stranded DNAs capable of catalyzing chemical reactions, including RNA ligation. Herein, we report a novel class of RNA ligase deoxyribozymes that utilize 5'-adenylated RNA (5'-AppRNA) as the donor substrate, mimicking the activated intermediates of protein-catalyzed RNA ligation. Four new DNAzymes were identified by in vitro selection from an N40 random DNA library and were shown to catalyze the intermolecular linear RNA-RNA ligation via the formation of a native 3'-5'-phosphodiester linkage. The catalytic activity is distinct from previously described RNA-ligating deoxyribozymes. Kinetic analyses revealed the optimal incubation conditions for high ligation yields and demonstrated a broad RNA substrate scope. Together with the smooth synthetic accessibility of 5'-adenylated RNAs, the new DNA enzymes are promising tools for the protein-free synthesis of long RNAs, for example containing precious modified nucleotides or fluorescent labels for biochemical and biophysical investigations.
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Affiliation(s)
- Carolin P. M. Scheitl
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany;
| | - Sandra Lange
- Agricultural Center, BASF SE, Speyerer Str 2, 67117 Limburgerhof, Germany;
| | - Claudia Höbartner
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany;
- Correspondence:
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7
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Neuner E, Micura R. Practical synthesis of N-(di- n-butylamino)methylene-protected 2-aminopurine riboside phosphoramidite for RNA solid-phase synthesis. MONATSHEFTE FUR CHEMIE 2019; 150:1941-1946. [PMID: 31929656 PMCID: PMC6936340 DOI: 10.1007/s00706-019-02502-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/09/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Eva Neuner
- Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Leopold-Franzens University, Innrain 80-82, Innsbruck, Austria
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8
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An artificial DNAzyme RNA ligase shows a reaction mechanism resembling that of cellular polymerases. Nat Catal 2019. [DOI: 10.1038/s41929-019-0290-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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9
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10
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Dhamodharan V, Kobori S, Yokobayashi Y. Large Scale Mutational and Kinetic Analysis of a Self-Hydrolyzing Deoxyribozyme. ACS Chem Biol 2017; 12:2940-2945. [PMID: 29058875 DOI: 10.1021/acschembio.7b00621] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deoxyribozymes are catalytic DNA sequences whose atomic structures are generally difficult to elucidate. Mutational analysis remains a principal approach for understanding and engineering deoxyribozymes with diverse catalytic activities. However, laborious preparation and biochemical characterization of individual sequences severely limit the number of mutants that can be studied biochemically. Here, we applied deep sequencing to directly measure the activities of self-hydrolyzing deoxyribozyme sequences in high throughput. First, all single and double mutants within the 15-base catalytic core of the deoxyribozyme I-R3 were assayed to unambiguously determine the tolerated and untolerated mutations at each position. Subsequently, 4096 deoxyribozyme variants with tolerated base substitutions at seven positions were kinetically assayed in parallel. We identified 533 active mutants whose first-order rate constants and activation energies were determined. The results indicate an isolated and narrow peak in the deoxyribozyme sequence space and provide a quantitative view of the effects of multiple mutations on the deoxyribozyme activity for the first time.
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Affiliation(s)
- V. Dhamodharan
- Nucleic Acid Chemistry and
Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 9040495, Japan
| | - Shungo Kobori
- Nucleic Acid Chemistry and
Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 9040495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and
Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 9040495, Japan
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11
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Hara T, Kodama T, Takegaki Y, Morihiro K, Ito KR, Obika S. Synthesis and Properties of 7-Deazapurine- and 8-Aza-7-deazapurine-Locked Nucleic Acid Analogues: Effect of the Glycosidic Torsion Angle. J Org Chem 2016; 82:25-36. [DOI: 10.1021/acs.joc.6b02525] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Takashi Hara
- Graduate
School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuya Kodama
- Graduate
School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Yumi Takegaki
- Graduate
School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kunihiko Morihiro
- Graduate
School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kosuke Ramon Ito
- Graduate
School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Satoshi Obika
- Graduate
School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
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12
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Zhu J, Li Z, Wang Q, Liu Y, He J. The contribution of adenines in the catalytic core of 10-23 DNAzyme improved by the 6-amino group modifications. Bioorg Med Chem Lett 2016; 26:4462-4465. [DOI: 10.1016/j.bmcl.2016.07.076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/13/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
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13
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Behera AK, Schlund KJ, Mason AJ, Alila KO, Han M, Grout RL, Baum DA. Enhanced deoxyribozyme-catalyzed RNA ligation in the presence of organic cosolvents. Biopolymers 2016; 99:382-91. [PMID: 23529690 DOI: 10.1002/bip.22191] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 11/16/2012] [Accepted: 11/26/2012] [Indexed: 02/06/2023]
Abstract
Deoxyribozyme and aptamer selections are typically conducted in aqueous buffer solutions. Using nonaqueous cosolvents in selection experiments will help expand the activity of deoxyribozymes with non-oligonucleotide substrates and will allow identification of new aptamers for nonprotein targets. We undertook in vitro selections utilizing a small amount of methanol in the reaction to keep the herbicides alachlor and atrazine in solution with the goal of identifying deoxyribozymes that require these herbicides for activity. The resulting deoxyribozymes successfully catalyze RNA ligation, but do not require alachlor or atrazine. Surprisingly, some of these deoxyribozymes displayed better catalytic activity in the presence of methanol over just aqueous buffer. We investigated several organic cosolvents to see if this enhancement was limited to methanol and found that other cosolvents, including ethanol, DMSO, and DMF, supported activity; in some cases, greater enhancement was observed. On the basis of these results, we tested two other previously identified RNA-ligating deoxyribozymes to assess their tolerance of cosolvents and determined that different deoxyribozymes showed different responses to the cosolvents. Our results demonstrate that deoxyribozymes can tolerate and, in some cases, display enhanced activity in alternative solvent conditions. These findings will facilitate the development of responsive deoxyribozyme systems utilizing components with limited water solubility.
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Affiliation(s)
- Anit K Behera
- Department of Chemistry, Saint Louis University, 3501 Laclede Avenue, St. Louis, MO, 63103
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14
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Crystal structure of a DNA catalyst. Nature 2016; 529:231-4. [PMID: 26735012 DOI: 10.1038/nature16471] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/20/2015] [Indexed: 01/13/2023]
Abstract
Catalysis in biology is restricted to RNA (ribozymes) and protein enzymes, but synthetic biomolecular catalysts can also be made of DNA (deoxyribozymes) or synthetic genetic polymers. In vitro selection from synthetic random DNA libraries identified DNA catalysts for various chemical reactions beyond RNA backbone cleavage. DNA-catalysed reactions include RNA and DNA ligation in various topologies, hydrolytic cleavage and photorepair of DNA, as well as reactions of peptides and small molecules. In spite of comprehensive biochemical studies of DNA catalysts for two decades, fundamental mechanistic understanding of their function is lacking in the absence of three-dimensional models at atomic resolution. Early attempts to solve the crystal structure of an RNA-cleaving deoxyribozyme resulted in a catalytically irrelevant nucleic acid fold. Here we report the crystal structure of the RNA-ligating deoxyribozyme 9DB1 (ref. 14) at 2.8 Å resolution. The structure captures the ligation reaction in the post-catalytic state, revealing a compact folding unit stabilized by numerous tertiary interactions, and an unanticipated organization of the catalytic centre. Structure-guided mutagenesis provided insights into the basis for regioselectivity of the ligation reaction and allowed remarkable manipulation of substrate recognition and reaction rate. Moreover, the structure highlights how the specific properties of deoxyribose are reflected in the backbone conformation of the DNA catalyst, in support of its intricate three-dimensional organization. The structural principles underlying the catalytic ability of DNA elucidate differences and similarities in DNA versus RNA catalysts, which is relevant for comprehending the privileged position of folded RNA in the prebiotic world and in current organisms.
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15
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Functional Hallmarks of a Catalytic DNA that Makes Lariat RNA. Chemistry 2015; 22:3720-8. [DOI: 10.1002/chem.201503238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Indexed: 12/25/2022]
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16
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Abstract
Catalysis is a fundamental chemical concept, and many kinds of catalysts have considerable practical value. Developing entirely new catalysts is an exciting challenge. Rational design and screening have provided many new small-molecule catalysts, and directed evolution has been used to optimize or redefine the function of many protein enzymes. However, these approaches have inherent limitations that prompt the pursuit of different kinds of catalysts using other experimental methods. Nature evolved RNA enzymes, or ribozymes, for key catalytic roles that in modern biology are limited to phosphodiester cleavage/ligation and amide bond formation. Artificial DNA enzymes, or deoxyribozymes, have great promise for a broad range of catalytic activities. They can be identified from unbiased (random) sequence populations as long as the appropriate in vitro selection strategies can be implemented for their identification. Notably, in vitro selection is different in key conceptual and practical ways from rational design, screening, and directed evolution. This Account describes the development by in vitro selection of DNA catalysts for many different kinds of covalent modification reactions of peptide and protein substrates, inspired in part by our earlier work with DNA-catalyzed RNA ligation reactions. In one set of studies, we have sought DNA-catalyzed peptide backbone cleavage, with the long-term goal of artificial DNA-based proteases. We originally anticipated that amide hydrolysis should be readily achieved, but in vitro selection instead surprisingly led to deoxyribozymes for DNA phosphodiester hydrolysis; this was unexpected because uncatalyzed amide bond hydrolysis is 10(5)-fold faster. After developing a suitable selection approach that actively avoids DNA hydrolysis, we were able to identify deoxyribozymes for hydrolysis of esters and aromatic amides (anilides). Aliphatic amide cleavage remains an ongoing focus, including via inclusion of chemically modified DNA nucleotides in the catalyst, which we have recently found to enable this cleavage reaction. In numerous other efforts, we have investigated DNA-catalyzed peptide side chain modification reactions. Key successes include nucleopeptide formation (attachment of oligonucleotides to peptide side chains) and phosphatase and kinase activities (removal and attachment of phosphoryl groups to side chains). Through all of these efforts, we have learned the importance of careful selection design, including the frequent need to develop specific "capture" reactions that enable the selection process to provide only those DNA sequences that have the desired catalytic functions. We have established strategies for identifying deoxyribozymes that accept discrete peptide and protein substrates, and we have obtained data to inform the key choice of random region length at the outset of selection experiments. Finally, we have demonstrated the viability of modular deoxyribozymes that include a small-molecule-binding aptamer domain, although the value of such modularity is found to be minimal, with implications for many selection endeavors. Advances such as those summarized in this Account reveal that DNA has considerable catalytic abilities for biochemically relevant reactions, specifically including covalent protein modifications. Moreover, DNA has substantially different, and in many ways better, characteristics than do small molecules or proteins for a catalyst that is obtained "from scratch" without demanding any existing information on catalyst structure or mechanism. Therefore, prospects are very strong for continued development and eventual practical applications of deoxyribozymes for peptide and protein modification.
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Affiliation(s)
- Scott K. Silverman
- Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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17
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Turriani E, Höbartner C, Jovin TM. Mg2+-dependent conformational changes and product release during DNA-catalyzed RNA ligation monitored by Bimane fluorescence. Nucleic Acids Res 2014; 43:40-50. [PMID: 25505142 PMCID: PMC4288166 DOI: 10.1093/nar/gku1268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Among the deoxyribozymes catalyzing the ligation of two RNA substrates, 7S11 generates a branched RNA containing a 2',5'-linkage. We have attached the small fluorogenic probe Bimane to the triphosphate terminated RNA substrate and utilized emission intensity and anisotropy to follow structural rearrangements leading to a catalytically active complex upon addition of Mg(2+). Bimane coupled to synthetic oligonucleotides is quenched by nearby guanines via photoinduced electron transfer. The degree of quenching is sensitive to changes in the base pairing of the residues involved and in their distances to the probe. These phenomena permit the characterization of various sequential processes in the assembly and function of 7S11: binding of Mg(2+) to the triphosphate moiety, release of quenching of the probe by the 5'-terminal G residues of R-RNA as they engage in secondary base-pair interactions, local rearrangement into a distinct active conformation, and continuous release of the Bimane-labeled pyrophosphate during the course of reaction at 37°C. It was possible to assign equilibrium and rate constants and structural interpretations to the sequence of conformational transitions and catalysis, information useful for optimizing the design of next generation deoxyribozymes. The fluorescent signatures, thermodynamic equilibria and catalytic function of numerous mutated (base/substituted) molecules were examined.
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Affiliation(s)
- Elisa Turriani
- Scuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, I-56126 Pisa, Italy Laboratory for Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Claudia Höbartner
- Max Planck Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany and Institute for Organic and Biomolecular Chemistry, Georg August University Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Thomas M Jovin
- Laboratory for Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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18
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Wawrzyniak-Turek K, Höbartner C. Enzymatic combinatorial nucleoside deletion scanning mutagenesis of functional RNA. Chem Commun (Camb) 2014; 50:10937-40. [PMID: 25097037 DOI: 10.1039/c4cc04719b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We describe a general and simple method to identify catalytically and structurally important nucleotides in functional RNAs. Our approach is based on statistical replacement of each nucleoside with a non-nucleosidic spacer (C3 linker, Δ), followed by separation of active library variants and readout of interference effects by analysis of enzymatic primer extension reactions.
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Affiliation(s)
- Katarzyna Wawrzyniak-Turek
- Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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19
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Li Z, Liu Y, Liu G, Zhu J, Zheng Z, Zhou Y, He J. Position-specific modification with imidazolyl group on10-23 DNAzyme realized catalytic activity enhancement. Bioorg Med Chem 2014; 22:4010-7. [PMID: 24961875 DOI: 10.1016/j.bmc.2014.05.070] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 12/24/2022]
Abstract
Nucleoside analogues with imidazolyl and histidinyl groups were synthesized for site-specific modification on the catalytic core of 10-23 DNAzyme. The distinct position-dependent effect of imidazolyl group was observed. Positive effect at A9 position was always observed. The pH- and Mg(2+)-dependence of the imidazolyl-modified DNAzymes suggested that imidazolyl group in 10-23 DNAzyme probably plays a dual role, its hydrogen bonding ability and spacial occupation play the favorable influence on the catalytic conformation of the modified DNAzymes. This research demonstrated that the catalytic performance of DNAzymes could be enhanced by incorporation of additional functional groups. Chemical modification is a feasible approach toward more efficient DNAzymes for therapeutic and biotechnological applications.
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Affiliation(s)
- Zhiwen Li
- College of Life Sciences, Guizhou University, Guiyang 550025, China
| | - Yang Liu
- School of Pharmacological Sciences, Guangxi Medical University, Nanning 530021, China
| | - Gaofeng Liu
- College of Life Sciences, Guizhou University, Guiyang 550025, China
| | - Junfei Zhu
- College of Life Sciences, Guizhou University, Guiyang 550025, China
| | - Zhibing Zheng
- School of Pharmacological Sciences, Guangxi Medical University, Nanning 530021, China; Beijing Institute of Pharmacology and Toxicology, Taiping Road 27, Beijing 100850, China
| | - Ying Zhou
- College of Life Sciences, Guizhou University, Guiyang 550025, China
| | - Junlin He
- College of Life Sciences, Guizhou University, Guiyang 550025, China; Beijing Institute of Pharmacology and Toxicology, Taiping Road 27, Beijing 100850, China.
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Deoxyribozyme-Mediated Ligation for Incorporating EPR Spin Labels and Reporter Groups into RNA. Methods Enzymol 2014; 549:85-104. [DOI: 10.1016/b978-0-12-801122-5.00004-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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21
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Javadi-Zarnaghi F, Höbartner C. Lanthanide cofactors accelerate DNA-catalyzed synthesis of branched RNA. J Am Chem Soc 2013; 135:12839-48. [PMID: 23895365 DOI: 10.1021/ja406162z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Most deoxyribozymes (DNA catalysts) require metal ions as cofactors for catalytic activity, with Mg(2+), Mn(2+), and Zn(2+) being the most represented activators. Trivalent transition-metal ions have been less frequently considered. Rare earth ions offer attractive properties for studying metal ion binding by biochemical and spectroscopic methods. Here we report the effect of lanthanide cofactors, in particular terbium (Tb(3+)), for DNA-catalyzed synthesis of 2',5'-branched RNA. We found up to 10(4)-fold increased ligation rates for the 9F7 deoxribozyme using 100 μM Tb(3+) and 7 mM Mg(2+), compared to performing the reaction with 7 mM Mg(2+) alone. Combinatorial mutation interference analysis (CoMA) was used to identify nucleotides in the catalytic region of 9F7 that are essential for ligation activity with different metal ion combinations. A minimized version of the DNA enzyme sustained high levels of Tb(3+)-assisted activity. Sensitized luminescence of Tb(3+) bound to DNA in combination with DMS probing and DNase I footprinting results supported the CoMA data. The accelerating effect of Tb(3+) was confirmed for related RNA-ligating deoxyribozymes, pointing toward favorable activation of internal 2'-OH nucleophiles. The results of this study offer fundamental insights into nucleotide requirements for DNA-catalyzed RNA ligation and will be beneficial for practical applications that utilize 2',5'-branched RNA.
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Affiliation(s)
- Fatemeh Javadi-Zarnaghi
- Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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22
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Domínguez-Martín A, Johannsen S, Sigel A, Operschall BP, Song B, Sigel H, Okruszek A, González-Pérez JM, Niclós-Gutiérrez J, Sigel RKO. Intrinsic acid-base properties of a hexa-2'-deoxynucleoside pentaphosphate, d(ApGpGpCpCpT): neighboring effects and isomeric equilibria. Chemistry 2013; 19:8163-81. [PMID: 23595830 DOI: 10.1002/chem.201203330] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 12/09/2012] [Indexed: 02/02/2023]
Abstract
The intrinsic acid-base properties of the hexa-2'-deoxynucleoside pentaphosphate, d(ApGpGpCpCpT) [=(A1∙G2∙G3∙C4∙C5∙T6)=(HNPP)⁵⁻] have been determined by ¹H NMR shift experiments. The pKa values of the individual sites of the adenosine (A), guanosine (G), cytidine (C), and thymidine (T) residues were measured in water under single-strand conditions (i.e., 10% D₂O, 47 °C, I=0.1 M, NaClO₄). These results quantify the release of H⁺ from the two (N7)H⁺ (G∙G), the two (N3)H⁺ (C∙C), and the (N1)H⁺ (A) units, as well as from the two (N1)H (G∙G) and the (N3)H (T) sites. Based on measurements with 2'-deoxynucleosides at 25 °C and 47 °C, they were transferred to pKa values valid in water at 25 °C and I=0.1 M. Intramolecular stacks between the nucleobases A1 and G2 as well as most likely also between G2 and G3 are formed. For HNPP three pKa clusters occur, that is those encompassing the pKa values of 2.44, 2.97, and 3.71 of G2(N7)H⁺, G3(N7)H⁺, and A1(N1)H⁺, respectively, with overlapping buffer regions. The tautomer populations were estimated, giving for the release of a single proton from five-fold protonated H₅(HNPP)(±) , the tautomers (G2)N7, (G3)N7, and (A1)N1 with formation degrees of about 74, 22, and 4%, respectively. Tautomer distributions reveal pathways for proton-donating as well as for proton-accepting reactions both being expected to be fast and to occur practically at no "cost". The eight pKa values for H₅(HNPP)(±) are compared with data for nucleosides and nucleotides, revealing that the nucleoside residues are in part affected very differently by their neighbors. In addition, the intrinsic acidity constants for the RNA derivative r(A1∙G2∙G3∙C4∙C5∙U6), where U=uridine, were calculated. Finally, the effect of metal ions on the pKa values of nucleobase sites is briefly discussed because in this way deprotonation reactions can easily be shifted to the physiological pH range.
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Affiliation(s)
- Alicia Domínguez-Martín
- Institute of Inorganic Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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Bruno JG. A review of therapeutic aptamer conjugates with emphasis on new approaches. Pharmaceuticals (Basel) 2013; 6:340-57. [PMID: 24276022 PMCID: PMC3816688 DOI: 10.3390/ph6030340] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 03/09/2013] [Accepted: 03/11/2013] [Indexed: 12/14/2022] Open
Abstract
The potential to emulate or enhance antibodies with nucleic acid aptamers while lowering costs has prompted development of new aptamer-protein, siRNA, drug, and nanoparticle conjugates. Specific focal points of this review discuss DNA aptamers covalently bound at their 3' ends to various proteins for enhanced stability and greater pharmacokinetic lifetimes in vivo. The proteins can include Fc tails of IgG for opsonization, and the first component of complement (C1q) to trigger complement-mediated lysis of antibiotic-resistant Gram negative bacteria, cancer cells and possibly some parasites during vulnerable stages. In addition, the 3' protein adduct may be a biotoxin, enzyme, or may simply be human serum albumin (HSA) or a drug known to bind HSA, thereby retarding kidney and other organ clearance and inhibiting serum exonucleases. In this review, the author summarizes existing therapeutic aptamer conjugate categories and describes his patented concept for PCR-based amplification of double-stranded aptamers followed by covalent attachment of proteins or other agents to the chemically vulnerable overhanging 3' adenine added by Taq polymerase. PCR amplification of aptamers could dramatically lower the current $2,000/gram cost of parallel chemical oligonucleotide synthesis, thereby enabling mass production of aptamer-3'-protein or drug conjugates to better compete against expensive humanized monoclonal antibodies.
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Affiliation(s)
- John G Bruno
- Operational Technologies Corporation, 4100 NW Loop 410, Suite 230, San Antonio, TX 78229, USA.
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Samanta B, Höbartner C. Mutationsanalyse funktionaler DNA durch statistische Nucleosiddeletion. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Samanta B, Höbartner C. Combinatorial nucleoside-deletion-scanning mutagenesis of functional DNA. Angew Chem Int Ed Engl 2013; 52:2995-9. [PMID: 23371361 DOI: 10.1002/anie.201208103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 01/03/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Biswajit Samanta
- Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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RNA-Cleaving DNA Enzymes and Their Potential Therapeutic Applications as Antibacterial and Antiviral Agents. FROM NUCLEIC ACIDS SEQUENCES TO MOLECULAR MEDICINE 2012. [PMCID: PMC7119987 DOI: 10.1007/978-3-642-27426-8_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
DNA catalysts are synthetic single-stranded DNA molecules that have been identified by in vitro selection from random sequence DNA pools. The most prominent representatives of DNA catalysts (also known as DNA enzymes, deoxyribozymes, or DNAzymes) catalyze the site-specific cleavage of RNA substrates. Two distinct groups of RNA-cleaving DNA enzymes are the 10-23 and 8-17 enzymes. A typical RNA-cleaving DNA enzyme consists of a catalytic core and two short binding arms which form Watson–Crick base pairs with the RNA targets. RNA cleavage is usually achieved with the assistance of metal ions such as Mg2+, Ca2+, Mn2+, Pb2+, or Zn2+, but several chemically modified DNA enzymes can cleave RNA in the absence of divalent metal ions. A number of studies have shown the use of 10-23 DNA enzymes for modest downregulation of therapeutically relevant RNA targets in cultured cells and in whole mammals. Here we focus on mechanistic aspects of RNA-cleaving DNA enzymes and their potential to silence therapeutically appealing viral and bacterial gene targets. We also discuss delivery options and challenges involved in DNA enzyme-based therapeutic strategies.
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28
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Wong OY, Mulcrone AE, Silverman SK. DNA-catalyzed reductive amination. Angew Chem Int Ed Engl 2011; 50:11679-84. [PMID: 21994131 DOI: 10.1002/anie.201104976] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/22/2011] [Indexed: 11/12/2022]
Affiliation(s)
- On Yi Wong
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
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