1
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Schaudy E, Ibañez-Redín G, Parlar E, Somoza MM, Lietard J. Nonaqueous Oxidation in DNA Microarray Synthesis Improves the Oligonucleotide Quality and Preserves Surface Integrity on Gold and Indium Tin Oxide Substrates. Anal Chem 2024; 96:2378-2386. [PMID: 38285499 PMCID: PMC10867803 DOI: 10.1021/acs.analchem.3c04166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/29/2023] [Accepted: 12/29/2023] [Indexed: 01/30/2024]
Abstract
Nucleic acids attached to electrically conductive surfaces are very frequently used platforms for sensing and analyte detection as well as for imaging. Synthesizing DNA on these uncommon substrates and preserving the conductive layer is challenging as this coating tends to be damaged by the repeated use of iodine and water, which is the standard oxidizing medium following phosphoramidite coupling. Here, we thoroughly investigate the use of camphorsulfonyl oxaziridine (CSO), a nonaqueous alternative to I2/H2O, for the synthesis of DNA microarrays in situ. We find that CSO performs equally well in producing high hybridization signals on glass microscope slides, and CSO also protects the conductive layer on gold and indium tin oxide (ITO)-coated slides. DNA synthesis on conductive substrates with CSO oxidation yields microarrays of quality approaching that of conventional glass with intact physicochemical properties.
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Affiliation(s)
- Erika Schaudy
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Gisela Ibañez-Redín
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Etkin Parlar
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Mark M. Somoza
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, Vienna 1090, Austria
- Leibniz-Institute
for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Straße 30, Freising 85354, Germany
- Chair
of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, Freising 85354, Germany
| | - Jory Lietard
- Institute
of Inorganic Chemistry, University of Vienna, Josef-Holaubek-Platz 2, Vienna 1090, Austria
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2
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Chen X, Xie L, Zhang C, Tian S, Tang Z, Tian W, Lu P, Yang X. A Convenient Method for the Synthesis of 2'-O-Cyanoethylated Nucleotides and Their Application in the Solid-Phase Synthesis of Related RNA Analogs. Curr Protoc 2023; 3:e923. [PMID: 37962485 DOI: 10.1002/cpz1.923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Although small interfering RNA (siRNA) is a key player among gene inhibition therapeutics, there are many obstacles to the development of siRNA drugs due to inherent properties of oligonucleotides, including the unsatisfactory stability of unmodified siRNA, poor pharmacokinetic distribution, and the toxicity induced by off-target effects. To maximize treatment potency, chemical modification of siRNA has undoubtedly been the most successful strategy by far. Widely applied modifications include phosphorothioate linkages, 2'-O-methyl modifications, and 2'-fluoro modifications, among others. To extend the family of chemical modifications for oligonucleotides, 2'-O-cyanoethylated RNA analogs were developed through the replacement of the 2'-hydroxyl group with a 2'-O-cyanoethyl group (-OCH2 CH2 CN). This modification can provide several advantages over unmodified RNA, such as increased stability, improved binding affinity to complementary DNA or RNA strands, and resistance to degradation by cellular nucleases. The 2'-O-cyanoethyl-modified RNAs not only are applied in RNA silencing machinery but also act as research tools for studying RNA structure and function or for developing RNA-based diagnostics. Therefore, the efficient synthesis, deprotection, purification, and characterization of 2'-O-cyanoethylated RNAs deserves more attention. This protocol describes the chemical synthesis of 2'-O-cyanoethylated nucleotides and the solid-phase synthesis, deprotection, and purification of 2'-O-cyanoethylated RNAs. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Preparation of 6-N-dimethylformamidyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl adenosine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 2: Preparation of 4-N-acetyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl cytidine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 3: Preparation of 2-N-dimethylformamidyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl guanine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 4: Preparation of 5'-O-dimethoxytrityl-2'-O-2-cyanoethyl uridine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 5: Solid-phase synthesis of 2'-O-cyanoethylated RNA analogs Basic Protocol 6: Deprotection and purification of synthesized 2'-O-cyanoethyl-RNAs.
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Affiliation(s)
- Xuan Chen
- Sirnaomics Ltd. Suzhou, Suzhou, China
| | - Long Xie
- Sirnaomics Ltd. Suzhou, Suzhou, China
| | | | - Shen Tian
- Sirnaomics Ltd. Suzhou, Suzhou, China
| | - Zeyu Tang
- Sirnaomics Ltd. Suzhou, Suzhou, China
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3
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Khalaf JK, Bess LS, Walsh LM, Ward JM, Johnson CL, Livesay MT, Jackson KJ, Evans JT, Ryter KT, Bazin-Lee HG. Diamino Allose Phosphates: Novel, Potent, and Highly Stable Toll-like Receptor 4 Agonists. J Med Chem 2023; 66:13900-13917. [PMID: 37847244 DOI: 10.1021/acs.jmedchem.3c00724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Most known synthetic toll-like receptor 4 (TLR4) agonists are carbohydrate-based lipid-A mimetics containing several fatty acyl chains, including a labile 3-O-acyl chain linked to the C-3 position of the non-reducing sugar known to undergo cleavage impacting stability and resulting in loss of activity. To overcome this inherent instability, we rationally designed a new class of chemically more stable synthetic TLR4 ligands that elicit robust innate and adaptive immune responses. This new class utilized a diamino allose phosphate (DAP) scaffold containing a nonhydrolyzable 3-amide bond instead of the classical 3-ester. Accordingly, the DAPs have significantly improved thermostability in aqueous formulations and potency relative to other known natural and synthetic TLR4 ligands. Furthermore, the DAP analogues function as potent vaccine adjuvants to enhance influenza-specific antibodies in mice and provide protection against lethal influenza virus challenges. This novel set of TLR4 ligands show promise as next-generation vaccine adjuvants and stand-alone immunomodulators.
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Affiliation(s)
- Juhienah K Khalaf
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Laura S Bess
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Lois M Walsh
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Janine M Ward
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Craig L Johnson
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Mark T Livesay
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Konner J Jackson
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Jay T Evans
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Kendal T Ryter
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
| | - Hélène G Bazin-Lee
- Inimmune Corporation, 1121 E Broadway, Suite 121, Missoula, Montana 59802, United States
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4
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Kawamoto Y, Wu Y, Takahashi Y, Takakura Y. Development of nucleic acid medicines based on chemical technology. Adv Drug Deliv Rev 2023; 199:114872. [PMID: 37244354 DOI: 10.1016/j.addr.2023.114872] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/01/2023] [Accepted: 05/12/2023] [Indexed: 05/29/2023]
Abstract
Oligonucleotide-based therapeutics have attracted attention as an emerging modality that includes the modulation of genes and their binding proteins related to diseases, allowing us to take action on previously undruggable targets. Since the late 2010s, the number of oligonucleotide medicines approved for clinical uses has dramatically increased. Various chemistry-based technologies have been developed to improve the therapeutic properties of oligonucleotides, such as chemical modification, conjugation, and nanoparticle formation, which can increase nuclease resistance, enhance affinity and selectivity to target sites, suppress off-target effects, and improve pharmacokinetic properties. Similar strategies employing modified nucleobases and lipid nanoparticles have been used for developing coronavirus disease 2019 mRNA vaccines. In this review, we provide an overview of the development of chemistry-based technologies aimed at using nucleic acids for developing therapeutics over the past several decades, with a specific emphasis on the structural design and functionality of chemical modification strategies.
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Affiliation(s)
- Yusuke Kawamoto
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
| | - You Wu
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Yuki Takahashi
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Yoshinobu Takakura
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
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5
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Bege M, Borbás A. The Medicinal Chemistry of Artificial Nucleic Acids and Therapeutic Oligonucleotides. Pharmaceuticals (Basel) 2022; 15:ph15080909. [PMID: 35893733 PMCID: PMC9330994 DOI: 10.3390/ph15080909] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/17/2022] [Accepted: 07/20/2022] [Indexed: 02/04/2023] Open
Abstract
Nucleic acids play a central role in human biology, making them suitable and attractive tools for therapeutic applications. While conventional drugs generally target proteins and induce transient therapeutic effects, nucleic acid medicines can achieve long-lasting or curative effects by targeting the genetic bases of diseases. However, native oligonucleotides are characterized by low in vivo stability due to nuclease sensitivity and unfavourable physicochemical properties due to their polyanionic nature, which are obstacles to their therapeutic use. A myriad of synthetic oligonucleotides have been prepared in the last few decades and it has been shown that proper chemical modifications to either the nucleobase, the ribofuranose unit or the phosphate backbone can protect the nucleic acids from degradation, enable efficient cellular uptake and target localization ensuring the efficiency of the oligonucleotide-based therapy. In this review, we present a summary of structure and properties of artificial nucleic acids containing nucleobase, sugar or backbone modifications, and provide an overview of the structure and mechanism of action of approved oligonucleotide drugs including gene silencing agents, aptamers and mRNA vaccines.
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Affiliation(s)
- Miklós Bege
- Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary;
- Institute of Healthcare Industry, University of Debrecen, Nagyerdei körút 98, 4032 Debrecen, Hungary
- MTA-DE Molecular Recognition and Interaction Research Group, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Anikó Borbás
- Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary;
- National Laboratory of Virology, University of Pécs, Ifjúság útja 20, 7624 Pécs, Hungary
- Correspondence:
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6
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Vasquez G, Migawa MT, Wan WB, Low A, Tanowitz M, Swayze EE, Seth PP. Evaluation of Phosphorus and Non-Phosphorus Neutral Oligonucleotide Backbones for Enhancing Therapeutic Index of Gapmer Antisense Oligonucleotides. Nucleic Acid Ther 2021; 32:40-50. [PMID: 34698585 DOI: 10.1089/nat.2021.0064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The phosphorothioate (PS) linkage in an essential component of therapeutic oligonucleotides. PS in the DNA region of gapmer antisense oligonucleotides (ASOs) supports RNaseH1 activity and enhances nuclease stability. PS also promotes binding to plasma, cell surface, and intracellular proteins, which facilitates tissue distribution, cellular uptake, and endosomal escape of PS ASOs. We recently showed that site-specific replacement of PS in the DNA gap with methoxylpropyl phosphonate (MOP) linkages can enhance the therapeutic index of gapmer ASOs. In this article, we explored 18 phosphorus- and non-phosphorus-based neutral backbone modifications to determine the structure-activity relationship of neutral linkages for enhancing therapeutic index. Replacing MOP with other alkyl phosphonate and phosphotriester linkages enhanced therapeutic index, but these linkages were susceptible to chemical degradation during oligonucleotide deprotection from solid supports following synthesis. Replacing MOP with non-phosphorus linkages resulted in improved chemical stability, but these linkages were introduced into ASOs as nucleotide dimers, which limits their versatility. Overall, linkages such as isopropyl and isobutyl phosphonates and O-isopropyl and O-tetrahydrofuranosyl phosphotriesters, formacetal, and C3-amide showed improved activity in mice relative to MOP. Our data suggest that site-specific incorporation of any neutral backbone linkage can improve therapeutic index, but the size, hydrophobicity, and RNA-binding affinity of the linkage influence ASO activity.
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Affiliation(s)
- Guillermo Vasquez
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Michael T Migawa
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - W Brad Wan
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Audrey Low
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Michael Tanowitz
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Eric E Swayze
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Punit P Seth
- Department of Medicinal Chemistry, Ionis Pharmaceuticals, Carlsbad, California, USA
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7
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Knouse KW, Flood DT, Vantourout JC, Schmidt MA, Mcdonald IM, Eastgate MD, Baran PS. Nature Chose Phosphates and Chemists Should Too: How Emerging P(V) Methods Can Augment Existing Strategies. ACS CENTRAL SCIENCE 2021; 7:1473-1485. [PMID: 34584948 PMCID: PMC8461637 DOI: 10.1021/acscentsci.1c00487] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Indexed: 05/27/2023]
Abstract
Phosphate linkages govern life as we know it. Their unique properties provide the foundation for many natural systems from cell biology and biosynthesis to the backbone of nucleic acids. Phosphates are ideal natural moieties; existing as ionized species in a stable P(V)-oxidation state, they are endowed with high stability but exhibit enzymatically unlockable potential. Despite intense interest in phosphorus catalysis and condensation chemistry, organic chemistry has not fully embraced the potential of P(V) reagents. To be sure, within the world of chemical oligonucleotide synthesis, modern approaches utilize P(III) reagent systems to create phosphate linkages and their analogs. In this Outlook, we present recent studies from our laboratories suggesting that numerous exciting opportunities for P(V) chemistry exist at the nexus of organic synthesis and biochemistry. Applications to the synthesis of stereopure antisense oligonucleotides, cyclic dinucleotides, methylphosphonates, and phosphines are reviewed as well as chemoselective modification to peptides, proteins, and nucleic acids. Finally, an outlook into what may be possible in the future with P(V) chemistry is previewed, suggesting these examples represent just the tip of the iceberg.
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Affiliation(s)
- Kyle W. Knouse
- Elsie
Biotechnologies, 4955
Directors Place, San Diego, California 92121, United States
- Department
of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dillon T. Flood
- Elsie
Biotechnologies, 4955
Directors Place, San Diego, California 92121, United States
- Department
of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Julien C. Vantourout
- Department
of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Michael A. Schmidt
- Chemical
and Synthetic Development, Bristol Myers
Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Ivar M. Mcdonald
- Small
Molecule Drug Discovery, Bristol Myers Squibb, 100 Binney Street, Cambridge, Massachusetts 02142, United States
| | - Martin D. Eastgate
- Chemical
and Synthetic Development, Bristol Myers
Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Phil S. Baran
- Elsie
Biotechnologies, 4955
Directors Place, San Diego, California 92121, United States
- Department
of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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8
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Xu R, Gao Z, Yu Y, Tang Y, Tian D, Chen T, Chen Y, Xu G, Shi E, Tang W. A facile and practical preparation of P-chiral phosphine oxides. Chem Commun (Camb) 2021; 57:3335-3338. [PMID: 33665653 DOI: 10.1039/d1cc00646k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A practical and cost-effective synthetic method of P-chiral diarylalkyl, aryldialkyl, and triaryl phosphine oxides by using readily available chiral diphenyl-2-pyrrolidinemethanol as the auxiliary is developed. The long-standing racemization issue during solvolysis has been addressed and well controlled by employing a suitable solvent, a low reaction temperature, and an appropriate reaction time.
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Affiliation(s)
- Ronghua Xu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
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9
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Clavé G, Reverte M, Vasseur JJ, Smietana M. Modified internucleoside linkages for nuclease-resistant oligonucleotides. RSC Chem Biol 2021; 2:94-150. [PMID: 34458777 PMCID: PMC8341215 DOI: 10.1039/d0cb00136h] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/16/2020] [Indexed: 12/21/2022] Open
Abstract
In the past few years, several drugs derived from nucleic acids have been approved for commercialization and many more are in clinical trials. The sensitivity of these molecules to nuclease digestion in vivo implies the need to exploit resistant non-natural nucleotides. Among all the possible modifications, the one concerning the internucleoside linkage is of particular interest. Indeed minor changes to the natural phosphodiester may result in major modifications of the physico-chemical properties of nucleic acids. As this linkage is a key element of nucleic acids' chemical structures, its alteration can strongly modulate the plasma stability, binding properties, solubility, cell penetration and ultimately biological activity of nucleic acids. Over the past few decades, many research groups have provided knowledge about non-natural internucleoside linkage properties and participated in building biologically active nucleic acid derivatives. The recent renewing interest in nucleic acids as drugs, demonstrated by the emergence of new antisense, siRNA, aptamer and cyclic dinucleotide molecules, justifies the review of all these studies in order to provide new perspectives in this field. Thus, in this review we aim at providing the reader insights into modified internucleoside linkages that have been described over the years whose impact on annealing properties and resistance to nucleases have been evaluated in order to assess their potential for biological applications. The syntheses of modified nucleotides as well as the protocols developed for their incorporation within oligonucleotides are described. Given the intended biological applications, the modifications described in the literature that have not been tested for their resistance to nucleases are not reported.
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Affiliation(s)
| | - Maeva Reverte
- IBMM, Univ. Montpellier, CNRS, ENSCM Montpellier France
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10
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Xu D, Rivas-Bascón N, Padial NM, Knouse KW, Zheng B, Vantourout JC, Schmidt MA, Eastgate MD, Baran PS. Enantiodivergent Formation of C-P Bonds: Synthesis of P-Chiral Phosphines and Methylphosphonate Oligonucleotides. J Am Chem Soc 2020; 142:5785-5792. [PMID: 32109356 DOI: 10.1021/jacs.9b13898] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phosphorus Incorporation (PI, abbreviated Π) reagents for the modular, scalable, and stereospecific synthesis of chiral phosphines and methylphosphonate nucleotides are reported. Synthesized from trans-limonene oxide, this reagent class displays an unexpected reactivity profile and enables access to chemical space distinct from that of the Phosphorus-Sulfur Incorporation reagents previously disclosed. Here, the adaptable phosphorus(V) scaffold enables sequential addition of carbon nucleophiles to produce a variety of enantiopure C-P building blocks. Addition of three carbon nucleophiles to Π, followed by stereospecific reduction, affords useful P-chiral phosphines; introduction instead of a single methyl group reveals the first stereospecific synthesis of methylphosphonate oligonucleotide precursors. While both Π enantiomers are available, only one isomer is required-the order of nucleophile addition controls the absolute stereochemistry of the final product through a unique enantiodivergent design.
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Affiliation(s)
- Dongmin Xu
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nazaret Rivas-Bascón
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Natalia M Padial
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kyle W Knouse
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Bin Zheng
- Chemistry Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Julien C Vantourout
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Michael A Schmidt
- Chemistry Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Martin D Eastgate
- Chemistry Development, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Phil S Baran
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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11
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Migawa MT, Shen W, Wan WB, Vasquez G, Oestergaard ME, Low A, De Hoyos CL, Gupta R, Murray S, Tanowitz M, Bell M, Nichols JG, Gaus H, Liang XH, Swayze EE, Crooke ST, Seth PP. Site-specific replacement of phosphorothioate with alkyl phosphonate linkages enhances the therapeutic profile of gapmer ASOs by modulating interactions with cellular proteins. Nucleic Acids Res 2019; 47:5465-5479. [PMID: 31034558 PMCID: PMC6582325 DOI: 10.1093/nar/gkz247] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/21/2019] [Accepted: 04/02/2019] [Indexed: 01/04/2023] Open
Abstract
Phosphorothioate-modified antisense oligonucleotides (PS-ASOs) interact with a host of plasma, cell-surface and intracellular proteins which govern their therapeutic properties. Given the importance of PS backbone for interaction with proteins, we systematically replaced anionic PS-linkages in toxic ASOs with charge-neutral alkylphosphonate linkages. Site-specific incorporation of alkyl phosphonates altered the RNaseH1 cleavage patterns but overall rates of cleavage and activity versus the on-target gene in cells and in mice were only minimally affected. However, replacing even one PS-linkage at position 2 or 3 from the 5'-side of the DNA-gap with alkylphosphonates reduced or eliminated toxicity of several hepatotoxic gapmer ASOs. The reduction in toxicity was accompanied by the absence of nucleolar mislocalization of paraspeckle protein P54nrb, ablation of P21 mRNA elevation and caspase activation in cells, and hepatotoxicity in mice. The generality of these observations was further demonstrated for several ASOs versus multiple gene targets. Our results add to the types of structural modifications that can be used in the gap-region to enhance ASO safety and provide insights into understanding the biochemistry of PS ASO protein interactions.
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Affiliation(s)
- Michael T Migawa
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Wen Shen
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - W Brad Wan
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | | | | | - Audrey Low
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | | | - Ruchi Gupta
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Susan Murray
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Michael Tanowitz
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Melanie Bell
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Joshua G Nichols
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Hans Gaus
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Xue-Hai Liang
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Eric E Swayze
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Stanley T Crooke
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Punit P Seth
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
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12
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Kostov O, Liboska R, Páv O, Novák P, Rosenberg I. Solid-Phase Synthesis of Phosphorothioate/Phosphonothioate and Phosphoramidate/Phosphonamidate Oligonucleotides. Molecules 2019; 24:molecules24101872. [PMID: 31096640 PMCID: PMC6571627 DOI: 10.3390/molecules24101872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/09/2019] [Accepted: 05/14/2019] [Indexed: 11/30/2022] Open
Abstract
We have developed a robust solid-phase protocol which allowed the synthesis of chimeric oligonucleotides modified with phosphodiester and O-methylphosphonate linkages as well as their P-S and P-N variants. The novel O-methylphosphonate-derived modifications were obtained by oxidation, sulfurization, and amidation of the O-methyl-(H)-phosphinate internucleotide linkage introduced into the oligonucleotide chain by H-phosphonate chemistry using nucleoside-O-methyl-(H)-phosphinates as monomers. The H-phosphonate coupling followed by oxidation after each cycle enabled us to successfully combine H-phosphonate and phosphoramidite chemistries to synthesize diversely modified oligonucleotide strands.
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Affiliation(s)
- Ondřej Kostov
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | - Radek Liboska
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | - Ondřej Páv
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | - Pavel Novák
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | - Ivan Rosenberg
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
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13
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Diastereomers of a mono-substituted phosphoryl guanidine trideoxyribonucleotide: Isolation and properties. Biochem Biophys Res Commun 2019; 513:807-811. [PMID: 31000201 DOI: 10.1016/j.bbrc.2019.04.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/03/2019] [Indexed: 12/19/2022]
Abstract
Recently, a new type of nucleic acid analogues with modified phosphate group, namely, phosphoryl guanidine oligonucleotides, has been described. In the present work, we assess the difference between diastereomers of a mono-substituted phosphoryl guanidine oligonucleotide and analyze their resistance to nuclease digestion. Individual diastereomers ('fast' and 'slow') of a trideoxynucleotide d (TpCp*A) were isolated by reverse-phase HPLC. Snake venom phosphodiesterase digestion showed that the native trideoxynucleotide was fully degraded after 30 min, whereas both 'fast' and 'slow' diastereomers of d (TpCp*A) were not completely digested even after 7 days. UV and CD spectra revealed similarities in the structure of the diastereomers. Structural analysis by 1D and 2D NMR spectroscopy also uncovered significant similarity in the properties of Rp and Sp diastereomers. Structural analysis of nuclear Overhauser effect spectroscopy (NOESY) data and restrained molecular dynamics methods showed very flexible single-stranded oligonucleotide structures. Detailed computational analysis of restraint penalty energies via restrained molecular dynamics simulations with the 2D NMR interproton distance data allowed us to conclude that most likely, the 'fast' isomer is the Sp diastereomer, and the 'slow' isomer is the Rp diastereomer.
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14
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Evich M, Spring-Connell AM, Germann MW. Impact of modified ribose sugars on nucleic acid conformation and function. HETEROCYCL COMMUN 2017. [DOI: 10.1515/hc-2017-0056] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AbstractThe modification of the ribofuranose in nucleic acids is a widespread method of manipulating the activity of nucleic acids. These alterations, however, impact the local conformation and chemical reactivity of the sugar. Changes in the conformation and dynamics of the sugar moiety alter the local and potentially global structure and plasticity of nucleic acids, which in turn contributes to recognition, binding of ligands and enzymatic activity of proteins. This review article introduces the conformational properties of the (deoxy)ribofuranose ring and then explores sugar modifications and how they impact local and global structure and dynamics in nucleic acids.
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Affiliation(s)
- Marina Evich
- Georgia State University, Department of Chemistry, 50 Decatur St. SE, Atlanta, GA 30303, USA
| | | | - Markus W. Germann
- Georgia State University, Department of Chemistry, 50 Decatur St. SE, Atlanta, GA 30303, USA
- Georgia State University, Department of Biology, P.O. 4010, Atlanta, GA 30303, USA
- Georgia State University, Neuroscience Institute, P.O. 5030, Atlanta, GA 30303, USA
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15
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Abstract
Oligonucleotide-based therapeutics have made rapid progress in the clinic for treatment of a variety of disease indications. Unmodified oligonucleotides are polyanionic macromolecules with poor drug-like properties. Over the past two decades, medicinal chemists have identified a number of chemical modification and conjugation strategies which can improve the nuclease stability, RNA-binding affinity, and pharmacokinetic properties of oligonucleotides for therapeutic applications. In this perspective, we present a summary of the most commonly used nucleobase, sugar and backbone modification, and conjugation strategies used in oligonucleotide medicinal chemistry.
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Affiliation(s)
- W Brad Wan
- Department of Medicinal Chemistry, Ionis Pharmaceuticals , 2855 Gazelle Court, Carlsbad, California 92010, United States
| | - Punit P Seth
- Department of Medicinal Chemistry, Ionis Pharmaceuticals , 2855 Gazelle Court, Carlsbad, California 92010, United States
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16
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Chemical synthesis of RNA with site-specific methylphosphonate modifications. Methods 2016; 107:79-88. [PMID: 27037236 PMCID: PMC5405801 DOI: 10.1016/j.ymeth.2016.03.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/25/2016] [Accepted: 03/26/2016] [Indexed: 11/21/2022] Open
Abstract
Methylphosphonate(mP)-modified RNA serves as valuable probe to evaluate biomolecular interactions between the nucleic acid backbone and binding partners, such as proteins or small molecules. Here, we describe an efficient workflow for the synthesis of RNA with a single mP modification in diastereomerically pure form. While the automated assembly of mP-modified RNA is straightforward, its deprotection under basic conditions is challenging; a carefully optimized step-by-step procedure is provided. In addition, we demonstrate purification and separation strategies for the RP and SP-configurated RNA diastereomers using a combination of anion-exchange and reversed-phase HPLC, and comment on troubleshooting if their separation appears difficult. Furthermore, we demonstrate the stereochemical assignment of short RP and SP mP-modified RNA diastereomers based on 2D ROESY NMR spectroscopy and we report on the impact of the mP modification on thermal and thermodynamic stabilities of RNA-DNA hybrid and RNA-RNA duplexes.
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Li H, Lee T, Dziubla T, Pi F, Guo S, Xu J, Li C, Haque F, Liang XJ, Guo P. RNA as a stable polymer to build controllable and defined nanostructures for material and biomedical applications. NANO TODAY 2015; 10:631-655. [PMID: 26770259 PMCID: PMC4707685 DOI: 10.1016/j.nantod.2015.09.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The value of polymers is manifested in their vital use as building blocks in material and life sciences. Ribonucleic acid (RNA) is a polynucleic acid, but its polymeric nature in materials and technological applications is often overlooked due to an impression that RNA is seemingly unstable. Recent findings that certain modifications can make RNA resistant to RNase degradation while retaining its authentic folding property and biological function, and the discovery of ultra-thermostable RNA motifs have adequately addressed the concerns of RNA unstability. RNA can serve as a unique polymeric material to build varieties of nanostructures including nanoparticles, polygons, arrays, bundles, membrane, and microsponges that have potential applications in biomedical and material sciences. Since 2005, more than a thousand publications on RNA nanostructures have been published in diverse fields, indicating a remarkable increase of interest in the emerging field of RNA nanotechnology. In this review, we aim to: delineate the physical and chemical properties of polymers that can be applied to RNA; introduce the unique properties of RNA as a polymer; review the current methods for the construction of RNA nanostructures; describe its applications in material, biomedical and computer sciences; and, discuss the challenges and future prospects in this field.
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Affiliation(s)
- Hui Li
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Taek Lee
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea
| | - Thomas Dziubla
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA
| | - Fengmei Pi
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Sijin Guo
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Jing Xu
- Laboratory of Nanomedicine and Nanosafety, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing 100190, China
| | - Chan Li
- Laboratory of Nanomedicine and Nanosafety, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing 100190, China
| | - Farzin Haque
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Xing-Jie Liang
- Laboratory of Nanomedicine and Nanosafety, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing 100190, China
| | - Peixuan Guo
- Nanobiotechnology Center, Markey Cancer Center, and Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
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18
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Wickstrom E. DNA and RNA derivatives to optimize distribution and delivery. Adv Drug Deliv Rev 2015; 87:25-34. [PMID: 25912659 DOI: 10.1016/j.addr.2015.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 12/27/2022]
Abstract
Synthetic, complementary DNA single strands and short interfering RNA double strands have been found to inhibit the expression of animal, plant, and viral genes in cells, animals, and patients, in a dose dependent and sequence specific manner. DNAs and RNAs, however, are readily digested in biological systems. Hence, chemists are obliged to design and synthesize nuclease-resistant analogs of normal DNA (Fig. 1).
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19
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Role of a ribosomal RNA phosphate oxygen during the EF-G-triggered GTP hydrolysis. Proc Natl Acad Sci U S A 2015; 112:E2561-8. [PMID: 25941362 DOI: 10.1073/pnas.1505231112] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Elongation factor-catalyzed GTP hydrolysis is a key reaction during the ribosomal elongation cycle. Recent crystal structures of G proteins, such as elongation factor G (EF-G) bound to the ribosome, as well as many biochemical studies, provide evidence that the direct interaction of translational GTPases (trGTPases) with the sarcin-ricin loop (SRL) of ribosomal RNA (rRNA) is pivotal for hydrolysis. However, the precise mechanism remains elusive and is intensively debated. Based on the close proximity of the phosphate oxygen of A2662 of the SRL to the supposedly catalytic histidine of EF-G (His87), we probed this interaction by an atomic mutagenesis approach. We individually replaced either of the two nonbridging phosphate oxygens at A2662 with a methyl group by the introduction of a methylphosphonate instead of the natural phosphate in fully functional, reconstituted bacterial ribosomes. Our major finding was that only one of the two resulting diastereomers, the SP methylphosphonate, was compatible with efficient GTPase activation on EF-G. The same trend was observed for a second trGTPase, namely EF4 (LepA). In addition, we provide evidence that the negative charge of the A2662 phosphate group must be retained for uncompromised activity in GTP hydrolysis. In summary, our data strongly corroborate that the nonbridging proSP phosphate oxygen at the A2662 of the SRL is critically involved in the activation of GTP hydrolysis. A mechanistic scenario is supported in which positioning of the catalytically active, protonated His87 through electrostatic interactions with the A2662 phosphate group and H-bond networks are key features of ribosome-triggered activation of trGTPases.
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20
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Seth PP, Swayze EE. Unnatural Nucleoside Analogs for Antisense Therapy. METHODS AND PRINCIPLES IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1002/9783527676545.ch12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Tomaszewska A, Mourgues S, Guga P, Nawrot B, Pratviel G. A single nuclease-resistant linkage in DNA as a versatile tool for the characterization of DNA lesions: application to the guanine oxidative lesion "G+34" generated by metalloporphyrin/KHSO(5) reagent. Chem Res Toxicol 2012; 25:2505-12. [PMID: 23025551 DOI: 10.1021/tx300319y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxidation of an oligonucleotide containing a single nuclease-resistant phosphodiester link, a stereoisomerically pure methylphosphonate, by manganese (Mn-TMPyP) or iron (Fe-TMPyP) porphyrin associated to KHSO(5) allowed the isolation and characterization of a guanine lesion corresponding to an increase of mass of 34 amu as compared to guanine ("G+34"), namely, 5-carboxamido-5-formamido-2-iminohydantoin. Enzymatic digestion of the damaged oligonucleotide afforded, apart from the undamaged nucleotide monomer pool, a unique dinucleotide doubly modified with a methylphosphonate and an oxidized guanine base that is suitable for NMR analysis. The method can be applied to the study of any DNA lesion. More importantly, the method can be extended to the analysis of DNA damage in a sequence context. Any preselected residue in a DNA sequence may be individually analyzed by the easy introduction of a single nuclease-resistant link at the 3'- or 5'-position.
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22
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Liboska R, Snášel J, Barvík I, Buděšínský M, Pohl R, Točík Z, Páv O, Rejman D, Novák P, Rosenberg I. 4'-Alkoxy oligodeoxynucleotides: a novel class of RNA mimics. Org Biomol Chem 2011; 9:8261-7. [PMID: 22051918 DOI: 10.1039/c1ob06148h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
4'-Alkoxy-oligothymidylates were prepared as model compounds to study the influence of a C4'-alkoxy group on hybridisation. The phosphodiester homooligomers (15 units long) containing either a 4'-methoxy or 4'-(2-methoxyethoxy) group were found to display increased hybridisation with both dA(15) and rA(15) complementary counterparts compared to the natural oligothymidylate. In addition, we found their hybridisation behaviour to be similar to that of the regioisomeric 2'-O-methyl-oligothymidylate. The formed complexes (duplexes and triplexes) were studied using UV spectroscopy and polyacrylamide gel electrophoresis (PAGE). Structural background of the hybridization behaviour was examined using NMR and MDS. The favourable hybridisation properties of the 4'-alkoxyoligothymidylates indicated that 4'-alkoxy modified nucleotides are promising compounds for the assembly of chimeric oligonucleotides with tunable properties.
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Affiliation(s)
- Radek Liboska
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v. v. i., Flemingovo 2, 166 10 Prague 6, Czech Republic
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23
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Krishna H, Caruthers MH. Solid-phase synthesis, thermal denaturation studies, nuclease resistance, and cellular uptake of (oligodeoxyribonucleoside)methylborane phosphine-DNA chimeras. J Am Chem Soc 2011; 133:9844-54. [PMID: 21585202 DOI: 10.1021/ja201314q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The major hurdle associated with utilizing oligodeoxyribonucleotides for therapeutic purposes is their poor delivery into cells coupled with high nuclease susceptibility. In an attempt to combine the nonionic nature and high nuclease stability of the P-C bond of methylphosphonates with the high membrane permeability, low toxicity, and improved gene silencing ability of borane phosphonates, we have focused our research on the relatively unexplored methylborane phosphine (Me-P-BH(3)) modification. This Article describes the automated solid-phase synthesis of mixed-backbone oligodeoxynucleotides (ODNs) consisting of methylborane phosphine and phosphate or thiophosphate linkages (16-mers). Nuclease stability assays show that methylborane phosphine ODNs are highly resistant to 5' and 3' exonucleases. When hybridized to a complementary strand, the ODN:RNA duplex was more stable than its corresponding ODN:DNA duplex. The binding affinity of ODN:RNA duplex increased at lower salt concentration and approached that of a native DNA:RNA duplex under conditions close to physiological saline, indicating that the Me-P-BH(3) linkage is positively charged. Cellular uptake measurements indicate that these ODNs are efficiently taken up by cells even when the strand is 13% modified. Treatment of HeLa cells and WM-239A cells with fluorescently labeled ODNs shows significant cytoplasmic fluorescence when viewed under a microscope. Our results suggest that methylborane phosphine ODNs may prove very valuable as potential candidates in antisense research and RNAi.
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Affiliation(s)
- Heera Krishna
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309, USA
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24
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Wozniak LA, Bukowiecka-Matusiak M, Burzynska-Pedziwatr I, Stec WJ. Stereodefined dinucleoside (3′,5′)-propionamidophosphonates and β-cyanoethylphosphonates and their incorporation into modified oligonucleotides. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.01.153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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25
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Nagahama K, Veedu RN, Wengel J. Nuclease resistant methylphosphonate-DNA/LNA chimeric oligonucleotides. Bioorg Med Chem Lett 2009; 19:2707-9. [PMID: 19375912 DOI: 10.1016/j.bmcl.2009.03.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 10/21/2022]
Abstract
Synthesis of chimeric 9-mer oligonucleotides containing methylphosphonate-linkages and locked nucleic acid (LNA) monomers, their binding affinity towards complementary DNA and RNA, and their 3'-exonucleolytic stability are described. The obtained methylphosphonate-DNA/LNA chimeric oligonucleotides display similarly high RNA affinity and RNA selectivity as a corresponding 9-mer DNA/LNA chimeric oligonucleotide, but much higher resistance towards 3'-exonucleolytic degradation.
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Affiliation(s)
- Koji Nagahama
- Nucleic Acid Center, Department of Physics and Chemistry, University of Southern Denmark, Odense M, Denmark
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26
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Rasmussen LCV, Sperling-Petersen HU, Mortensen KK. Hitting bacteria at the heart of the central dogma: sequence-specific inhibition. Microb Cell Fact 2007; 6:24. [PMID: 17692125 PMCID: PMC1995221 DOI: 10.1186/1475-2859-6-24] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 08/10/2007] [Indexed: 12/16/2022] Open
Abstract
An important objective in developing new drugs is the achievement of high specificity to maximize curing effect and minimize side-effects, and high specificity is an integral part of the antisense approach. The antisense techniques have been extensively developed from the application of simple long, regular antisense RNA (asRNA) molecules to highly modified versions conferring resistance to nucleases, stability of hybrid formation and other beneficial characteristics, though still preserving the specificity of the original nucleic acids. These new and improved second- and third-generation antisense molecules have shown promising results. The first antisense drug has been approved and more are in clinical trials. However, these antisense drugs are mainly designed for the treatment of different human cancers and other human diseases. Applying antisense gene silencing and exploiting RNA interference (RNAi) are highly developed approaches in many eukaryotic systems. But in bacteria RNAi is absent, and gene silencing by antisense compounds is not nearly as well developed, despite its great potential and the intriguing possibility of applying antisense molecules in the fight against multiresistant bacteria. Recent breakthrough and current status on the development of antisense gene silencing in bacteria including especially phosphorothioate oligonucleotides (PS-ODNs), peptide nucleic acids (PNAs) and phosphorodiamidate morpholino oligomers (PMOs) will be presented in this review.
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Affiliation(s)
| | - Hans Uffe Sperling-Petersen
- Laboratory of BioDesign, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10 C, DK-8000 Aarhus C, Denmark
| | - Kim Kusk Mortensen
- Laboratory of BioDesign, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10 C, DK-8000 Aarhus C, Denmark
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Schell P, Laux WHG, Engels JW. Triarylmethyl Substituted 4,5-Dicyanoimidazoles as Activators for Rp-Diastereoselective Synthesis of TpN Dinucleoside Methylphosphonates. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319908044654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Wozniak LA, Janicka M, Bukowiecka-Matusiak M. Consequences ofP-Chirality in Chimeric 2′-O-Methyloligoribonucleotides with Stereoregular Methylphosphonothioate Linkages. European J Org Chem 2005. [DOI: 10.1002/ejoc.200500395] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Liu J, Déclais AC, McKinney SA, Ha T, Norman DG, Lilley DMJ. Stereospecific effects determine the structure of a four-way DNA junction. ACTA ACUST UNITED AC 2005; 12:217-28. [PMID: 15734649 DOI: 10.1016/j.chembiol.2004.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Revised: 11/08/2004] [Accepted: 12/03/2004] [Indexed: 11/25/2022]
Abstract
Conversion of a centrally located phosphate group to an electrically neutral methyl phosphonate in a four-way DNA junction can exert a major influence on its conformation. However, the effect is strongly dependent on stereochemistry. Substitution of the proR oxygen atom by methyl leads to conformational transition to the stacking conformer that places this phosphate at the point of strand exchange. By contrast, corresponding modification of the proS oxygen destabilizes this conformation of the junction. Single-molecule analysis shows that both molecules are in a dynamic equilibrium between alternative stacking conformers, but the configuration of the methyl phosphonate determines the bias of the conformational equilibrium. It is likely that the stereochemical environment of the methyl group affects the interaction with metal ions in the center of the junction.
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Affiliation(s)
- Jia Liu
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dundee DD1 5EH , United Kingdom
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30
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Wozniak L, Janicka M, Bukowiecka-Matusiak M. Chirality at phosphorus: hybrid duplexes of chimeric oligonucleotides containing methylphosphonothioate linkages with complementary DNA and RNA. J Organomet Chem 2005. [DOI: 10.1016/j.jorganchem.2004.12.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Peoc'h D, Swayze EE, Bhat B, Sanghvi YS. Synthesis of 2'-substituted MMI linked nucleosidic dimers: an optimization study in search of high affinity oligonucleotides for use in antisense constructs. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2004; 23:411-38. [PMID: 15043164 DOI: 10.1081/ncn-120028337] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The synthesis of a series of methylene(methylimino) (MMI) linked oligodeoxyribonucleotide dimers modified at the 2'-position with fluoro and/or methoxy groups and their incorporation into different sequences has been accomplished. From these dimers, bis 2'-OMe MMI dimer was selected for further studies based on its synthetic accessibility and the increased thermodynamic stability conferred upon oligonucleotides incorporating this modification.
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Affiliation(s)
- Didier Peoc'h
- Department of Medicinal Chemistry, Isis Pharmaceuticals, Inc., Carlsbad, California 92008, USA
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32
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Tian L, Claeboe CD, Hecht SM, Shuman S. Remote phosphate contacts trigger assembly of the active site of DNA topoisomerase IB. Structure 2004; 12:31-40. [PMID: 14725763 DOI: 10.1016/j.str.2003.11.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Vaccinia topoisomerase IB forms a covalent DNA-(3'-phosphotyrosyl)-enzyme intermediate at its target site 5'-CCCTTp downward arrow in duplex DNA. The contributions of backbone electrostatics and individual phosphate oxygens to the transesterification reaction were probed by introducing 22 single Rp and Sp methylphosphonate diastereomers at 11 positions flanking the cleavage site. Methyl groups at eight positions (four on the scissile strand and four on the nonscissile strand) inhibited the rate of single-turnover cleavage by factors of 50-50,000. Stereospecific interference was observed at several phosphates, thereby distinguishing simple electrostatic contributions from putative specific polar contacts to either the pro-Sp or pro-Rp oxygens. The functionally relevant phosphate oxygens are located on the minor groove face of the helix on which the scissile phosphodiester resides. Our findings, combined with available crystal structures of vaccinia and human topoisomerase IB, show how specific phosphate contacts remote from where chemistry occurs are critical for assembly of the active site.
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Affiliation(s)
- Ligeng Tian
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10021, USA
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33
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Olejniczak S, Sobczak M, Potrzebowski MJ, Polak M, Plavec J, Nawrot B. Assignment of absolute configuration at phosphorus of P-chiral diastereomers of deoxyribonucleoside methanephosphonamidates by means of NMR spectroscopy. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.03.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Tian L, Claeboe CD, Hecht SM, Shuman S. Guarding the genome: electrostatic repulsion of water by DNA suppresses a potent nuclease activity of topoisomerase IB. Mol Cell 2003; 12:199-208. [PMID: 12887905 DOI: 10.1016/s1097-2765(03)00263-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Type IB topoisomerases cleave and rejoin DNA strands through a stable covalent DNA-(3'-phosphotyrosyl)-enzyme intermediate. The stability of the intermediate is a two-edged sword; it preserves genome integrity during supercoil relaxation, but it also reinforces the toxicity of drugs and lesions that interfere with the DNA rejoining step. Here, we identify a key determinant of the stability of the complex by showing that introduction of an Sp or Rp methylphosphonate linkage at the cleavage site transforms topoisomerase IB into a potent endonuclease. The nuclease reaction entails formation and surprisingly rapid hydrolysis of a covalent enzyme-DNA methylphosphonate intermediate. The approximately 30,000-fold acceleration in the rate of hydrolysis of a methylphosphonate versus phosphodiester suggests that repulsion of water by the DNA phosphate anion suppresses the latent nuclease function of topoisomerase IB. These findings expose an Achilles' heel of topoisomerases as guardians of the genome, and they have broad implications for understanding enzymatic phosphoryl transfer.
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Affiliation(s)
- Ligeng Tian
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10021, USA
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35
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Hamma T, Miller PS. Interactions of hairpin oligo-2'-O-methylribonucleotides containing methylphosphonate linkages with HIV TAR RNA. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2003; 13:19-30. [PMID: 12691533 DOI: 10.1089/108729003764097313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Methylphosphonate-modified oligo-2'-O-methylribonucleotides 15-20 nucleotides (nt) in length were prepared whose sequences are complementary to the 5' and 3' sides of the upper hairpin of HIV trans-acting response element (TAR) RNA. These anti-TAR oligonucleotides (ODNs) form stable hairpins whose melting temperatures (Tm) range from 55 degrees C to 80 degrees C. Despite their rather high thermal stabilities, the hairpin oligo-2'-O-methylribonucleotides formed very stable complexes with TAR RNA, with dissociation constants in the nanomolar concentration range at 37 degrees C. The affinities of the hairpin oligomers for TAR RNA were influenced by the positions of the methylphosphonate linkages. The binding affinity was reduced approximately 17-fold by the presence of two methylphosphonate linkages in the TAR loop complementary region (TLCR) of the oligomer, whereas methylphosphonate linkages outside this region increased binding affinity approximately 3-fold. The configurations of the methylphosphonate linkages in the TLCR also affected binding affinity, with the RpRp isomer showing significantly higher binding than the SpSp isomer. In addition to serving as probes of the interactions between the oligomer and TAR RNA, the presence of the methylphosphonate linkages in combination with the hairpin structure increases the resistance of these oligomers to degradation by exonucleases found in mammalian serum. The combination of high binding affinity and nuclease resistance of the hairpin ODNs containing methylphosphonate linkages suggests their potential utility as antisense compounds.
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Affiliation(s)
- Tomoko Hamma
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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Lauritsen A, Dahl BM, Dahl O, Vester B, Wengel J. Methylphosphonate LNA: a locked nucleic acid with a methylphosphonate linkage. Bioorg Med Chem Lett 2003; 13:253-6. [PMID: 12482433 DOI: 10.1016/s0960-894x(02)00882-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Synthesis of an oligonucleotide containing one methylphosphonate locked nucleic acid (LNA) thymine monomer using the phosphoramidite approach is described. The binding affinity of this 9-mer methylphosphonate LNA towards complementary DNA and RNA oligonucleotides was increased compared to the reference DNA, but decreased compared to the reference LNA. In the 9-mer sequence context studied, introduction of a single methylphosphonate LNA monomer, contrary to a single LNA monomer, efficiently inhibits 3'-exonucleolytic degradation.
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Affiliation(s)
- Anne Lauritsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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Affiliation(s)
- Teresa A Golden
- Department of Biochemistry & Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama 36688, USA
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Okonogi TM, Alley SC, Harwood EA, Hopkins PB, Robinson BH. Phosphate backbone neutralization increases duplex DNA flexibility: a model for protein binding. Proc Natl Acad Sci U S A 2002; 99:4156-60. [PMID: 11929991 PMCID: PMC123618 DOI: 10.1073/pnas.072067799] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An important component of protein-DNA recognition is the charge neutralization of DNA backbone phosphates and subsequent protein-induced DNA bending. Replacement of phosphates by neutral methylphosphonates has previously been shown to be a model for protein-induced bending. In addition to bending, the neutralization process may change the inherent flexibility of the DNA--a feature never before tested. We have developed a method to measure the differential flexibility of duplex DNA when methylphosphonate substitutions are made and find that the local flexibility is increased up to 40%. These results imply that backbone-neutralization-dependent DNA flexibility augments DNA-binding motifs in protein-DNA recognition processes.
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Affiliation(s)
- Tamara M Okonogi
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA
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Gacs-Baitz E, Wozniak LA, Kajtar-Peredy M. Conformational properties of diastereomeric 5'-O-DMT-2'deoxythymidine 3'-O-(S-methyl-methanephosphonothiolate)s and -(se-methyl-methanephosphonoselenolate)s in solution as studied by NMR methods. Chirality 2000; 12:675-80. [PMID: 10984742 DOI: 10.1002/1520-636x(2000)12:9<675::aid-chir6>3.0.co;2-l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Stereochemical characterization of diastereomerically pure 5'-O-DMT-2'deoxythymidine 3'-O-(S-methyl-methanephosphonothiolate)s and -(Se-methyl-methane-phosphono-selenolate)s by NMR methods are reported. (1)H-(1)H, (1)H-(31)P, and (13)C-(31)P coupling constants and nuclear overhauser enhancement (NOE) connectivities from transverse cross-relaxation experiments in rotating frame (T-ROESY) were measured to correlate the conformational properties of the isomers with the absolute configurations at the phosphorus obtained from X-ray studies of the relatives of S(p) configured isomers. Conformational differences between the stereoisomers were found to be restricted to the different orientation of the C3'-O3'-P bond. The NMR data reflected the preferred epsilon(-) conformation for the S(p) isomers, while in the R(p) isomers the conformational equilibrium was shifted toward the epsilon(t) domain. These results also indicated that for 5'-protected mononucleotides the absolute configuration at the phosphorus atom can be inferred from the NOE experiments and the trends observed in vicinal carbon-phosphorus coupling constants. Copyright 2000 Wiley-Liss, Inc.
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Affiliation(s)
- E Gacs-Baitz
- Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Budapest, Hungary
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The 3rd Annual NIH Symposium on Therapeutic Oligonucleotides. Bethesda, Maryland, USA. December 4, 1998. Abstracts. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 1999; 9:359-431. [PMID: 10498436 DOI: 10.1089/oli.1.1999.9.359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Affiliation(s)
- R I Hogrefe
- Trilink Biotechnologies, Inc., San Diego, CA 92121, USA
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42
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Schweitzer M, Engels JW. Sequence specific hybridization properties of methylphosphonate oligodeoxynucleotides. J Biomol Struct Dyn 1999; 16:1177-88. [PMID: 10447202 DOI: 10.1080/07391102.1999.10508326] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Methylphosphonate oligodeoxynucleotides (MPO's) with isomerically pure Rp-configurated methylphosphonates (MP's) were synthesized by block coupling of ApT and TpA dinucleoside methylphosphonates (DMP's, p indicating MP-linkage). Oligonucleotide duplexes (20 mers) with these Rp-MP's showed almost the same melting temperatures (Tm) as those with phosphorodiester bonds. Further a dependence of the duplex stability from the nucleosides (bases) adjacent to the MP moiety was observed. For the first time thermodynamic parameters for the duplex to coil transition of isomerically pure MP's were determined from the concentration dependence of the Tm. CD-spectra of the duplexes show structural changes which can be associated with the transition to a compact helix with higher helix winding angle.
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Affiliation(s)
- M Schweitzer
- Institute of Organic Chemistry, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
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Schell P, Engels JW. Rp-Diastereoselective synthesis of dinucleoside methylphosphonates by the phosphoramidite approach. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)01972-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Debart F, Meyer A, Vasseur JJ, Rayner B. Anomeric inversion (from beta to alpha) in methylphosphonate oligonucleosides enhances their affinity for DNA and RNA. Nucleic Acids Res 1998; 26:4551-6. [PMID: 9753720 PMCID: PMC147882 DOI: 10.1093/nar/26.20.4551] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Here we report that the poor binding of methylphosphonate oligodeoxynucleosides (MP-ODNs) to their nucleic acid targets can be improved by additional inversion of the anomeric configuration (from beta to alpha) in the sugar moieties to give a new class of analogs, MP alpha-oligonucleosides. MP alpha-dT12and MP 5' alpha-d(TCTTAACCCACA) 3' were synthesized and their ability to form hybrids with complementary single stranded (ss)DNA and ssRNA, as well as with double stranded (ds)DNA, was evaluated. The thermal stability of hybrids formed with MP alpha-analogs was compared with the affinity of phosphodiester (PO) and phosphorothioate (PS) beta- and alpha-oligomers for their targets. Non-ionic MP alpha-oligonucleosides bound to their complementary DNA and RNA strands more tightly than their homologues with natural beta-anomeric configuration did. With DNA target, MP alpha-oligomers formed duplexes more stable than the corresponding natural PO beta-oligomer did. MP alpha-heteropolymer hybridized to RNA target better than PS beta-oligonucleotide did but the hybrid was less stable (DeltaTm-0.5 degrees C per mod.) than the hybrid formed with the natural PO beta-oligomer. Only MP alpha-dT12 bound to dsDNA target at low salt concentration (0.1 M NaCl).
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Affiliation(s)
- F Debart
- Laboratoire de Chimie Bio-organique, CC008, UMR 5625 CNRS-UM II, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France.
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Abstract
Synthetic oligonucleotide analogs have greatly aided our understanding of several biochemical processes. Efficient solid-phase and enzyme-assisted synthetic methods and the availability of modified base analogs have added to the utility of such oligonucleotides. In this review, we discuss the applications of synthetic oligonucleotides that contain backbone, base, and sugar modifications to investigate the mechanism and stereochemical aspects of biochemical reactions. We also discuss interference mapping of nucleic acid-protein interactions; spectroscopic analysis of biochemical reactions and nucleic acid structures; and nucleic acid cross-linking studies. The automation of oligonucleotide synthesis, the development of versatile phosphoramidite reagents, and efficient scale-up have expanded the application of modified oligonucleotides to diverse areas of fundamental and applied biological research. Numerous reports have covered oligonucleotides for which modifications have been made of the phosphodiester backbone, of the purine and pyrimidine heterocyclic bases, and of the sugar moiety; these modifications serve as structural and mechanistic probes. In this chapter, we review the range, scope, and practical utility of such chemically modified oligonucleotides. Because of space limitations, we discuss only those oligonucleotides that contain phosphate and phosphate analogs as internucleotidic linkages.
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Affiliation(s)
- S Verma
- Max-Planck-Institut für Experimentelle Medizin, Göttingen, Germany
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Tomky LA, Strauss-Soukup JK, Maher LJ. Effects of phosphate neutralization on the shape of the AP-1 transcription factor binding site in duplex DNA. Nucleic Acids Res 1998; 26:2298-305. [PMID: 9580678 PMCID: PMC147564 DOI: 10.1093/nar/26.10.2298] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Previous electrophoretic experiments suggest that the AP-1 site in duplex DNA bends in response to the pattern of amino acid charges distal to the basic region in bound bZIP proteins. The extent and direction of apparent DNA bending are consistent with the prediction that DNA will collapse locally upon asymmetric phosphate charge neutralization. To prove that asymmetric phosphate neutralization could produce the observed degree of DNA bending, the present experiments partially substitute anionic phosphate diesters in the AP-1 site with various numbers of neutral methylphosphonate linkages. DNA bending is induced toward the neutralized face of DNA. The degree of DNA bending induced by methylphosphonate substitution (approximately 3.5 degrees per neutralized phosphate) is comparable to that induced by GCN4 variants carrying increasing numbers of additional basic amino acids. It is plausible, therefore, that asymmetric phosphate neutralization is the cause of DNA bending in such complexes.
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Affiliation(s)
- L A Tomky
- Department of Biochemistry and Molecular Biology, Mayo Foundation, Rochester, MN 55905, USA
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Laurent A, Debart F, Rayner B. A new route to oligodeoxynucleoside phosphoramidates (PNH2). Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)01153-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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