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Zhang Z, Fu Y, Ju X, Zhang F, Zhang P, He M. Advances in Engineering Circular RNA Vaccines. Pathogens 2024; 13:692. [PMID: 39204292 PMCID: PMC11356823 DOI: 10.3390/pathogens13080692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 08/07/2024] [Accepted: 08/13/2024] [Indexed: 09/03/2024] Open
Abstract
Engineered circular RNAs (circRNAs) are a class of single-stranded RNAs with head-to-tail covalently linked structures that integrate open reading frames (ORFs) and internal ribosome entry sites (IRESs) with the function of coding and expressing proteins. Compared to mRNA vaccines, circRNA vaccines offer a more improved method that is safe, stable, and simple to manufacture. With the rapid revelation of the biological functions of circRNA and the success of Severe Acute Respiratory Coronavirus Type II (SARS-CoV-2) mRNA vaccines, biopharmaceutical companies and researchers around the globe are attempting to develop more stable circRNA vaccines for illness prevention and treatment. Nevertheless, research on circRNA vaccines is still in its infancy, and more work and assessment are needed for their synthesis, delivery, and use. In this review, based on the current understanding of the molecular biological properties and immunotherapeutic mechanisms of circRNA, we summarize the current preparation methods of circRNA vaccines, including design, synthesis, purification, and identification. We discuss their delivery strategies and summarize the challenges facing the clinical application of circRNAs to provide references for circRNA vaccine-related research.
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Affiliation(s)
- Zhongyan Zhang
- School of Pharmacy, Yantai University, Yantai 264005, China;
| | - Yuanlei Fu
- Yantai Key Laboratory of Nanomedicine & Advanced Preparations, Yantai Institute of Materia Medica, Yantai 264005, China; (Y.F.); (X.J.); (F.Z.)
| | - Xiaoli Ju
- Yantai Key Laboratory of Nanomedicine & Advanced Preparations, Yantai Institute of Materia Medica, Yantai 264005, China; (Y.F.); (X.J.); (F.Z.)
| | - Furong Zhang
- Yantai Key Laboratory of Nanomedicine & Advanced Preparations, Yantai Institute of Materia Medica, Yantai 264005, China; (Y.F.); (X.J.); (F.Z.)
| | - Peng Zhang
- School of Pharmacy, Yantai University, Yantai 264005, China;
| | - Meilin He
- Yantai Key Laboratory of Nanomedicine & Advanced Preparations, Yantai Institute of Materia Medica, Yantai 264005, China; (Y.F.); (X.J.); (F.Z.)
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Sharma NK, Dwivedi P, Bhushan R, Maurya PK, Kumar A, Dakal TC. Engineering circular RNA for molecular and metabolic reprogramming. Funct Integr Genomics 2024; 24:117. [PMID: 38918231 DOI: 10.1007/s10142-024-01394-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 06/10/2024] [Accepted: 06/17/2024] [Indexed: 06/27/2024]
Abstract
The role of messenger RNA (mRNA) in biological systems is extremely versatile. However, it's extremely short half-life poses a fundamental restriction on its application. Moreover, the translation efficiency of mRNA is also limited. On the contrary, circular RNAs, also known as circRNAs, are a common and stable form of RNA found in eukaryotic cells. These molecules are synthesized via back-splicing. Both synthetic circRNAs and certain endogenous circRNAs have the potential to encode proteins, hence suggesting the potential of circRNA as a gene expression machinery. Herein, we aim to summarize all engineering aspects that allow exogenous circular RNA (circRNA) to prolong the time that proteins are expressed from full-length RNA signals. This review presents a systematic engineering approach that have been devised to efficiently assemble circRNAs and evaluate several aspects that have an impact on protein production derived from. We have also reviewed how optimization of the key components of circRNAs, including the topology of vector, 5' and 3' untranslated sections, entrance site of the internal ribosome, and engineered aptamers could be efficiently impacting the translation machinery for molecular and metabolic reprogramming. Collectively, molecular and metabolic reprogramming present a novel way of regulating distinctive cellular features, for instance growth traits to neoplastic cells, and offer new possibilities for therapeutic inventions.
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Affiliation(s)
- Narendra Kumar Sharma
- Department of Bioscience and Biotechnology, Banasthali Vidyapith (Deemed University), P.O. Banasthali Vidyapith Distt. Tonk, Rajasthan, 304 022, India.
| | - Pragya Dwivedi
- Department of Bioscience and Biotechnology, Banasthali Vidyapith (Deemed University), P.O. Banasthali Vidyapith Distt. Tonk, Rajasthan, 304 022, India
| | - Ravi Bhushan
- Department of Zoology, M.S. College, Motihari, Bihar, India
| | - Pawan Kumar Maurya
- Department of Biochemistry, Central University of Haryana, Mahendergarh, 123031, Haryana, India
| | - Abhishek Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, Karnataka, India
- Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Tikam Chand Dakal
- Genome and Computational Biology Lab, Department of Biotechnology, Mohanlal Sukhadia University, Udaipur, Rajasthan, 313001, India.
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Xie J, Ye F, Deng X, Tang Y, Liang JY, Huang X, Sun Y, Tang H, Lei J, Zheng S, Zou Y. Circular RNA: A promising new star of vaccine. J Transl Int Med 2023; 11:372-381. [PMID: 38130633 PMCID: PMC10732498 DOI: 10.2478/jtim-2023-0122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Abstract
Circular RNAs (circRNAs) are a class of single-stranded RNAs with covalently closed structures. Owing to their not having 3' or 5' ends, circRNAs are highly durable and insusceptible to exonuclease-mediated degradation. Moreover, some circRNAs with certain structures are translatable, making them novel vaccines. Vaccines are efficient tools for immunotherapy, such as for the prevention of infectious diseases and cancer treatment. The immune system is activated during immunotherapy to fight against abnormal allies or invaders. CircRNA vaccines represent a potential new avenue in the vaccine era. Recently, several circRNA vaccines have been synthesized and tested in vitro and in vivo. Our review briefly introduces the current understanding of the biology and function of translatable circRNAs, molecular biology, synthetic methods, delivery of circRNA, and current circRNA vaccines. We also discussed the challenges and future directions in the field by summarizing the developments in circRNA vaccines in the past few years.
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Affiliation(s)
- Jindong Xie
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Fengxi Ye
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou510060, Guangdong Province, China
| | - Xinpei Deng
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Yuhui Tang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Jie-Ying Liang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Department of Medical Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou510000, Guangdong Province, China
| | - Xufeng Huang
- Department of Data Science and Visualization, Faculty of Informatics, University of Debrecen, Debrecen, Hungary
| | - Yuying Sun
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Hailin Tang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Jinsong Lei
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
| | - Shaoquan Zheng
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
- Breast Disease Center, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou510000, Guangdong Province, China
| | - Yutian Zou
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou510060, Guangdong Province, China
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Liu X, Zhang Y, Zhou S, Dain L, Mei L, Zhu G. Circular RNA: An emerging frontier in RNA therapeutic targets, RNA therapeutics, and mRNA vaccines. J Control Release 2022; 348:84-94. [PMID: 35649485 PMCID: PMC9644292 DOI: 10.1016/j.jconrel.2022.05.043] [Citation(s) in RCA: 100] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/17/2022] [Accepted: 05/25/2022] [Indexed: 12/13/2022]
Abstract
Circular RNAs (circRNA) is a class of natural (biogenic) or synthetic closed RNA without 5' or 3' ends. Meanwhile, their unique covalently-closed structures of circRNA prevent RNA degradation by exonucleases, thereby empowering them with high pharmaceutical stability and biostability relative to current standard-of-care linear mRNA. Natural circRNA can be non-coding RNAs as well as protein-coding RNA, the latter of which was recently discovered. The physiological functions of biogenic circRNAs, which largely remain elusive, include protein and gene sponges, cell activity modulators, and protein translation. The discovery that the circRNA levels can be correlated with some human diseases empowers circRNA with the potential as a novel type of disease biomarkers and a noncanonical class of therapeutic targets. Recently, synthetic circRNA have been engineered to explore their applications as a novel class of mRNA therapeutics and vaccines. In this review, we will discuss the current understanding of the biogenesis and physiological functions of natural circRNAs, the approaches to circRNA synthesis, and current research in the exploration of endogenous circRNAs as novel therapeutic targets and testing circRNAs as an emerging class of RNA therapeutics and vaccines.
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Affiliation(s)
- Xiang Liu
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Yu Zhang
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Shurong Zhou
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Lauren Dain
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Lei Mei
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Guizhi Zhu
- Department of Pharmaceutics and Center for Pharmaceutical Engineering and Sciences, School of Pharmacy, Institute for Structural Biology and Drug Discovery, The Developmental Therapeutics Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA.
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5
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Webb C, Ip S, Bathula NV, Popova P, Soriano SKV, Ly HH, Eryilmaz B, Nguyen Huu VA, Broadhead R, Rabel M, Villamagna I, Abraham S, Raeesi V, Thomas A, Clarke S, Ramsay EC, Perrie Y, Blakney AK. Current Status and Future Perspectives on MRNA Drug Manufacturing. Mol Pharm 2022; 19:1047-1058. [PMID: 35238565 PMCID: PMC8905930 DOI: 10.1021/acs.molpharmaceut.2c00010] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/20/2022]
Abstract
The coronavirus disease of 2019 (COVID-19) pandemic launched an unprecedented global effort to rapidly develop vaccines to stem the spread of the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2). Messenger ribonucleic acid (mRNA) vaccines were developed quickly by companies that were actively developing mRNA therapeutics and vaccines for other indications, leading to two mRNA vaccines being not only the first SARS-CoV-2 vaccines to be approved for emergency use but also the first mRNA drugs to gain emergency use authorization and to eventually gain full approval. This was possible partly because mRNA sequences can be altered to encode nearly any protein without significantly altering its chemical properties, allowing the drug substance to be a modular component of the drug product. Lipid nanoparticle (LNP) technology required to protect the ribonucleic acid (RNA) and mediate delivery into the cytoplasm of cells is likewise modular, as are technologies and infrastructure required to encapsulate the RNA into the LNP. This enabled the rapid adaptation of the technology to a new target. Upon the coattails of the clinical success of mRNA vaccines, this modularity will pave the way for future RNA medicines for cancer, gene therapy, and RNA engineered cell therapies. In this review, trends in the publication records and clinical trial registrations are tallied to show the sharp intensification in preclinical and clinical research for RNA medicines. Demand for the manufacturing of both the RNA drug substance (DS) and the LNP drug product (DP) has already been strained, causing shortages of the vaccine, and the rise in development and translation of other mRNA drugs in the coming years will exacerbate this strain. To estimate demand for DP manufacturing, the dosing requirements for the preclinical and clinical studies of the two approved mRNA vaccines were examined. To understand the current state of mRNA-LNP production, current methods and technologies are reviewed, as are current and announced global capacities for commercial manufacturing. Finally, a vision is rationalized for how emerging technologies such as self-amplifying mRNA, microfluidic production, and trends toward integrated and distributed manufacturing will shape the future of RNA manufacturing and unlock the potential for an RNA medicine revolution.
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Affiliation(s)
- Cameron Webb
- Strathclyde Institute of Pharmacy and
Biomedical Sciences, University of Strathclyde, 161 Cathedral Street,
Glasgow G4 0RE, United Kingdom
| | - Shell Ip
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Nuthan V. Bathula
- Michael Smith Laboratories & School of Biomedical
Engineering, University of British Columbia, 2185 East Mall,
Vancouver, British Columbia V6T 1Z4, Canada
| | - Petya Popova
- Michael Smith Laboratories & School of Biomedical
Engineering, University of British Columbia, 2185 East Mall,
Vancouver, British Columbia V6T 1Z4, Canada
| | - Shekinah K. V. Soriano
- Michael Smith Laboratories & School of Biomedical
Engineering, University of British Columbia, 2185 East Mall,
Vancouver, British Columbia V6T 1Z4, Canada
| | - Han Han Ly
- Michael Smith Laboratories & School of Biomedical
Engineering, University of British Columbia, 2185 East Mall,
Vancouver, British Columbia V6T 1Z4, Canada
| | - Burcu Eryilmaz
- Strathclyde Institute of Pharmacy and
Biomedical Sciences, University of Strathclyde, 161 Cathedral Street,
Glasgow G4 0RE, United Kingdom
| | - Viet Anh Nguyen Huu
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Richard Broadhead
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Martin Rabel
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Ian Villamagna
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Suraj Abraham
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Vahid Raeesi
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Anitha Thomas
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Samuel Clarke
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Euan C. Ramsay
- Precision NanoSystems Inc,
655 West Kent Avenue North Unit 50, Vancouver, British Columbia V6P 6T7,
Canada
| | - Yvonne Perrie
- Strathclyde Institute of Pharmacy and
Biomedical Sciences, University of Strathclyde, 161 Cathedral Street,
Glasgow G4 0RE, United Kingdom
| | - Anna K. Blakney
- Michael Smith Laboratories & School of Biomedical
Engineering, University of British Columbia, 2185 East Mall,
Vancouver, British Columbia V6T 1Z4, Canada
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6
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In vitro production of synthetic viral RNAs and their delivery into mammalian cells and the application of viral RNAs in the study of innate interferon responses. Methods 2020; 183:21-29. [PMID: 31682923 DOI: 10.1016/j.ymeth.2019.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 12/24/2022] Open
Abstract
Mammalian cells express different types of RNA molecules that can be classified as protein coding RNAs (mRNA) and non-coding RNAs (ncRNAs) the latter of which have housekeeping and regulatory functions in cells. Cellular RNAs are not recognized by cellular pattern recognition receptors (PRRs) and innate immunity is not activated. RNA viruses encode and express RNA molecules that usually differ from cell-specific RNAs and they include for instance 5'capped and 5'mono- and triphosphorylated RNAs, small viral RNAs and viral RNA-protein complexes called vRNPs. These molecules are recognized by certain members of Toll-like receptor (TLR) and RIG-I-like receptor (RLR) families leading to activation of innate immune responses and the production of antiviral cytokines, such as type I and type III interferons (IFNs). Virus-specific ssRNA and dsRNA molecules that mimic the viral genomic RNAs or their replication intermediates can efficiently be produced by bacteriophage T7 DNA-dependent RNA polymerase and bacteriophage phi6 RNA-dependent RNA polymerase, respectively. These molecules can then be delivered into mammalian cells and the mechanisms of activation of innate immune responses can be studied. In addition, synthetic viral dsRNAs can be processed to small interfering RNAs (siRNAs) by a Dicer enzyme to produce a swarm of antiviral siRNAs. Here we describe the biology of RNAs, their in vitro production and delivery into mammalian cells as well as how these molecules can be used to inhibit virus replication and to study the mechanisms of activation of the innate immune system.
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7
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Xia F, Zhang Q, Tian K, Zhu H. Theoretical studies on the effect of sulfur substitution for the methanolysis of cyclic and acyclic phosphate esters. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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8
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Abstract
We have performed density functional theory calculations on the alkaline hydrolysis of diethyl p-chlorophenyl phosphate and triethyl phosphate in the gas phase and in solution. It is found that the two hydrolysis reactions proceed through associative mechanism. The second step of hydrolysis reaction has a very low energy barrier fro diethyl p-chlorophenyl phosphate. For triethyl phosphate, the free energy barrier for the second step is higher both in the gas phase and in solution, indication the second step is the rate-determining step. The free energies of all stationary points and the free energy barrier for all the processes in solution are higher than those in the gas phase. Our calculations provide a comprehensive data set and allow re-interpretation of previous experimental and theoretical studies, and new experiment is proposed to trace reactions both in the gas phase and in solution.
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9
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Density functional calculations on alcoholysis and thiolysis of phosphate triesters: Stepwise or concerted? COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Xia F, Zhu H. Density functional calculations on the effect of sulfur substitution for 2'-hydroxypropyl-p-nitrophenyl phosphate: C-O vs. P-O bond cleavage. Bioorg Chem 2011; 40:99-107. [PMID: 22000806 DOI: 10.1016/j.bioorg.2011.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 09/10/2011] [Indexed: 10/17/2022]
Abstract
Density functional theory calculations have been used to investigate the intra-molecular attack of 2'-hydroxypropyl-p-nitrophenyl phosphate (HPpNP) and its analogous compound 2-thiouridyl-p-nitrophenyl phosphate (s-2'pNP). Bulk solvent effect has been tested at the geometry optimization level with the polarized continuum model. It is found that the P-path involving the intra-molecular attack at the phosphorus atom and C-path involving the attack at the beta carbon atom proceed through the S(N)2-type mechanism for HPpNP and s-2'pNP. The calculated results indicate that the P-path with the free energy barrier of about 11 kcal/mol is more accessible than the C-path for the intra-molecular attack of HPpNP, which favors the formation of the five-membered phosphate diester. While for s-2'pNP, the C-path with the free energy barrier of about 21 kcal/mol proceeds more favorably than the P-path. The calculated energy barriers of the favorable pathways for HPpNP and s-2'pNP are both in agreement with the experimental results.
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Affiliation(s)
- Futing Xia
- School of Chemistry, Sichuan University, Chengdu 610064, China
| | - Hua Zhu
- School of Chemistry, Sichuan University, Chengdu 610064, China; State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064, China.
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11
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Bellon L. Oligoribonucleotides with 2'-O-(tert-butyldimethylsilyl) groups. ACTA ACUST UNITED AC 2008; Chapter 3:Unit 3.6. [PMID: 18428846 DOI: 10.1002/0471142700.nc0306s01] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The chemical synthesis of oligoribonucleotides on solid support is routinely performed via the phosphoramidite method. However, the additional 2-OH function of the ribofuranosyl sugar requires suitable protection during oligoribonucleotide synthesis. This unit describes methods for 2-OH protection using the TBDMS group.
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Affiliation(s)
- L Bellon
- Ribozyme Pharmaceuticals, Boulder, Colorado, USA
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12
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Qin PZ, Haworth IS, Cai Q, Kusnetzow AK, Grant GPG, Price EA, Sowa GZ, Popova A, Herreros B, He H. Measuring nanometer distances in nucleic acids using a sequence-independent nitroxide probe. Nat Protoc 2008; 2:2354-65. [PMID: 17947978 DOI: 10.1038/nprot.2007.308] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This protocol describes the procedures for measuring nanometer distances in nucleic acids using a nitroxide probe that can be attached to any nucleotide within a given sequence. Two nitroxides are attached to phosphorothioates that are chemically substituted at specific sites of DNA or RNA. Inter-nitroxide distances are measured using a four-pulse double electron-electron resonance technique, and the measured distances are correlated to the parent structures using a Web-accessible computer program. Four to five days are needed for sample labeling, purification and distance measurement. The procedures described herein provide a method for probing global structures and studying conformational changes of nucleic acids and protein/nucleic acid complexes.
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Affiliation(s)
- Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744, USA.
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Sowa GZ, Qin PZ. Site-directed spin labeling studies on nucleic acid structure and dynamics. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2008; 82:147-97. [PMID: 18929141 DOI: 10.1016/s0079-6603(08)00005-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Site-directed spin labeling (SDSL) uses electron paramagnetic resonance (EPR) spectroscopy to monitor the behavior of a stable nitroxide radical attached at specific locations within a macromolecule such as protein, DNA, or RNA. Parameters obtained from EPR measurements, such as internitroxide distances and descriptions of the rotational motion of a nitroxide, provide unique information on features near the labeling site. With recent advances in solid-phase synthesis of nucleic acids and developments in EPR methodologies, particularly pulsed EPR technologies, SDSL has been increasingly used to study the structure and dynamics of DNA and RNA at the level of the individual nucleotides. This chapter summarizes the current SDSL studies on nucleic acids, with discussions focusing on literature from the last decade.
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Affiliation(s)
- Glenna Z Sowa
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
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14
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Liu Y, Gregersen BA, Lopez X, York DM. Density functional study of the in-line mechanism of methanolysis of cyclic phosphate and thiophosphate esters in solution: insight into thio effects in RNA transesterification. J Phys Chem B 2007; 109:19987-20003. [PMID: 16853584 DOI: 10.1021/jp053146z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density functional calculations of thio effects on the in-line mechanism of methanolysis of ethylene phosphate (a reverse reaction model for RNA phosphate transesterification) are presented. A total of 12 reaction mechanisms are examined using the B3LYP functional with large basis sets, and the effects of solvation were treated using the PCM, CPCM, and SM5 solvation models. Single thio substitutions at all of the distinct phosphoryl oxygen positions (2', 3', 5', pro-R) and a double thio substitution at the nonbridging (pro-R/pro-S) positions were considered. Profiles for each reaction were calculated in the dianionic and monoanionic/monoprotic states, corresponding to reaction models under alkaline and nonalkaline conditions, respectively. These models provide insight into the mechanisms of RNA transesterification thio effects and serve as a set of high-level quantum data that can be used in the design of new semiempirical quantum models for hybrid quantum mechanical/molecular mechanical simulations and linear-scaling electronic structure calculations.
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Affiliation(s)
- Yun Liu
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
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15
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Tsou D, Hampel A, Andrus A, Vinayak R. Large Scale Synthesis of Oligoribonucleotides on High-Loaded Polystyrene (HLP) Support. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/15257779508009486] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Gregersen BA, Lopez X, York DM. Hybrid QM/MM study of thio effects in transphosphorylation reactions: the role of solvation. J Am Chem Soc 2004; 126:7504-13. [PMID: 15198597 DOI: 10.1021/ja031815l] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transphosphorylation thio effects in solution are studied using hybrid QM/MM calculations with a d-orbital semiempirical Hamiltonian. Activated dynamics simulations were performed for a 3' ribose-phosphate model in an explicit 20 A sphere of TIP3P water surrounded by a solvent boundary potential, and free energy analysis was performed using the weighted histogram analysis method. Single thio-substitutions at all of the phosphoryl oxygen positions and a double thio-substitution at the nonbridging positions were considered. The reaction free energy profiles are compared with available experimental data, and the role of solvation on the barrier heights and reaction coordinate is discussed. These results provide an important step in the characterization of thio effects in reactions of biological phosphates that may aid in the interpretation of kinetic data and ultimately help to unravel the catalytic mechanisms of ribozymes.
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Affiliation(s)
- Brent A Gregersen
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA
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17
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Abstract
The chemical synthesis of RNA oligonucleotides is a valuable resource for biological research. A new approach for RNA synthesis that is now as reliable and efficient as DNA synthesis methods is described in this report. A 5'-O-silyl ether is used in conjunction with acid-labile orthoester protecting groups on the 2'-hydroxyls. RNA synthesis proceeds efficiently on commercial synthesizers in high yields. Analysis by anion-exchange HPLC shows that the quality and yields of RNA synthesized with this chemistry are unprecedented. Furthermore, this chemistry enables analysis and purification of stable 2'-O-protected RNA. This property serves to minimize possibilities for degradation of the RNA. In addition, it now possible to analyze troublesome sequences, which, when fully 2'-O-deprotected, do not easily resolve into one major conformation due to strong secondary structure. When ready for use, the RNA is easily 2'-O-deprotected in mild-acidic aqueous buffers in 30 min. This new RNA chemistry has enabled the routine high-quality synthesis of RNA oligonucleotides up to 50 bases in length regardless of sequence or secondary structure.
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Affiliation(s)
- S A Scaringe
- Dharmacon Research, Inc, 1376 Miners Drive, Lafayette, Colorado 80026, USA.
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18
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Metzler DE, Metzler CM, Sauke DJ. The Nucleic Acids. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50008-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Leclerc F, Llorente B, Cedergren R. Structure-function relationships of RNA: a modeling approach. Methods Enzymol 2000; 317:457-70. [PMID: 10829295 DOI: 10.1016/s0076-6879(00)17029-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- F Leclerc
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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20
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Affiliation(s)
- S A Scaringe
- Dharmacon Research, Inc., Boulder, Colorado 80301, USA
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21
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Abstract
The aminoacyl-tRNA synthetases are an ancient group of enzymes that catalyze the covalent attachment of an amino acid to its cognate transfer RNA. The question of specificity, that is, how each synthetase selects the correct individual or isoacceptor set of tRNAs for each amino acid, has been referred to as the second genetic code. A wealth of structural, biochemical, and genetic data on this subject has accumulated over the past 40 years. Although there are now crystal structures of sixteen of the twenty synthetases from various species, there are only a few high resolution structures of synthetases complexed with cognate tRNAs. Here we review briefly the structural information available for synthetases, and focus on the structural features of tRNA that may be used for recognition. Finally, we explore in detail the insights into specific recognition gained from classical and atomic group mutagenesis experiments performed with tRNAs, tRNA fragments, and small RNAs mimicking portions of tRNAs.
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Affiliation(s)
- P J Beuning
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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22
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Scaringe SA, Wincott FE, Caruthers MH. Novel RNA Synthesis Method Using 5‘-O-Silyl-2‘-O-orthoester Protecting Groups. J Am Chem Soc 1998. [DOI: 10.1021/ja980730v] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stephen A. Scaringe
- Dharmacon Research, Inc., Boulder, Colorado 80301 Ribozyme Pharmaceuticals, Inc., Boulder, Colorado 80301 University of Colorado, Boulder, Colorado 80309
| | - Francine E. Wincott
- Dharmacon Research, Inc., Boulder, Colorado 80301 Ribozyme Pharmaceuticals, Inc., Boulder, Colorado 80301 University of Colorado, Boulder, Colorado 80309
| | - Marvin H. Caruthers
- Dharmacon Research, Inc., Boulder, Colorado 80301 Ribozyme Pharmaceuticals, Inc., Boulder, Colorado 80301 University of Colorado, Boulder, Colorado 80309
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23
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24
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Matulic-Adamic J, Haeberli P, DiRenzo AB, Mokler VR, Maloney L, Beigelman L, Usman N, Wincott FE. Synthesis and Incorporation of 5″-Amino- and 5′-Mercapto-5′-Deoxy-2′-O-Methyl Nucleosides Into Hammerhead Ribozymes. ACTA ACUST UNITED AC 1997. [DOI: 10.1080/07328319708002545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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25
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Fell PL, Hudson AJ, Reynolds MA, Usman N, Akhtar S. Cellular uptake properties of a 2'-amino/2'-O-methyl-modified chimeric hammerhead ribozyme targeted to the epidermal growth factor receptor mRNA. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 1997; 7:319-26. [PMID: 9303183 DOI: 10.1089/oli.1.1997.7.319] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Catalytic RNA or ribozymes have important potential applications as molecular biological tools in the study of gene expression and as therapeutic inhibitors of disease-causing genes. Very little is known, however, about the cellular uptake mechanisms of exogenously delivered synthetic ribozymes. In this study, we have characterized the uptake properties of a synthetic, 2'-O-methyl-modified ribozyme containing U4/U7 amino groups within the catalytic core of the hammerhead motif. The cellular uptake of the internally [32P]-radiolabeled hammerhead ribozyme in U87-MG glioma cells was temperature, energy, and pH dependent and involved an active process that could be competed with cold ribozyme of the same chemistry and sequence, an all 2'-O-methyl-modified ribozyme of the same sequence, antisense PS-ODNs, and a variety of other polyanions (salmon sperm DNA, spermidine, dextran sulfate, and heparin). Subcellular distribution studies of fluorescently labeled ribozymes confirmed an extranuclear, punctate localization similar to that observed for an endosomal marker, dextran. Our study highlights that hammerhead ribozymes, despite exhibiting a defined secondary structure, enter cells by an endocytic mechanism that appears to be similar to that reported for a variety of antisense ODNs. These observations should facilitate the development of more efficient delivery systems.
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Affiliation(s)
- P L Fell
- Pharmaceutical Sciences Institute, Aston University, Birmingham, U.K
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26
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Bellon L, Workman C, Gonzalez C, Wincott F. Amino-Linked Ribozymes: Post-Synthetic Conjugation of Half-Ribozymes. ACTA ACUST UNITED AC 1997. [DOI: 10.1080/07328319708006113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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27
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Peracchi A, Beigelman L, Usman N, Herschlag D. Rescue of abasic hammerhead ribozymes by exogenous addition of specific bases. Proc Natl Acad Sci U S A 1996; 93:11522-7. [PMID: 8876168 PMCID: PMC38090 DOI: 10.1073/pnas.93.21.11522] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have synthesized 13 hammerhead ribozyme variants, each containing an abasic residue at a specific position of the catalytic core. The activity of each of the variants is significantly reduced. In four cases, however, activity can be rescued by exogenous addition of the missing base. For one variant, the rescue is 300-fold; for another, the rescue is to the wild-type level. This latter abasic variant (G10.1X) has been characterized in detail. Activation is specific for guanine, the base initially removed. In addition, the specificity for guanine versus adenine is substantially altered by replacing C with U in the opposite strand of the ribozyme. These results show that a binding site for a small, noncharged ligand can be created in a preexisting ribozyme structure. This has implications for structure-function analysis of RNA, and leads to speculations about evolution in an "RNA world" and about the potential therapeutic use of ribozymes.
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Affiliation(s)
- A Peracchi
- Department of Biochemistry, Stanford University, CA 94305-5307, USA
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28
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Jäschke A, Bald R, Nordhoff E, Hillenkamp F, Cech D, Erdmann VA, Fürste JP. Synthesis and Analytical Characterization of RNA-Polyethylene Glycol Conjugates. ACTA ACUST UNITED AC 1996. [DOI: 10.1080/07328319608002451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Schmidt S, Beigelman L, Karpeisky A, Usman N, Sorensen US, Gait MJ. Base and sugar requirements for RNA cleavage of essential nucleoside residues in internal loop B of the hairpin ribozyme: implications for secondary structure. Nucleic Acids Res 1996; 24:573-81. [PMID: 8604296 PMCID: PMC145697 DOI: 10.1093/nar/24.4.573] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The hairpin ribozyme is a small self-cleaving RNA that can be engineered for RNA cleavage in trans and has potential as a therapeutic agent. We have used a chemical synthesis approach to study the requirements of hairpin RNA cleavage for sugar and base moieties in residues of internal loop B, an essential region in one of the two ribozyme domains. Individual nucleosides were substituted by either a 2'-deoxy-nucleoside, an abasic residue, or a C3-spacer (propyl linker) and the abilities of the modified ribozymes to cleave an RNA substrate were studied in comparison with the wild-type ribozyme. From these results, together with previous studies, we propose a new model for the potential secondary structure of internal loop B of the hairpin ribozyme.
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Affiliation(s)
- S Schmidt
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK
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31
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Heidenreich O, Xu X, Swiderski P, Rossi JJ, Nerenberg M. Correlation of activity with stability of chemically modified ribozymes in nuclei suspension. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 1996; 6:111-8. [PMID: 8843325 DOI: 10.1089/oli.1.1996.6.111] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To examine hammerhead ribozyme activity in the nuclear environment, we have used nuclei isolated from HTLV-I tax transformed fibroblasts to evaluate ribozymes targeted against HTLV-I tax RNA. The ribozyme activity in nuclei suspension was strongly dependent on the resistance of the particular ribozyme to endogenous nucleases. A ribozyme containing exclusively 2'-deoxynucleotides in its stems cleaved target RNA by its catalytic activity in the absence of proteins and caused degradation in their presence by induction of nuclear RNase H activity. A ribozyme containing 2'-amino- and 2'-fluoropyrimidine nucleosides in combination with terminal phosphorothioate linkages was significantly more stable in nuclei suspension and also exhibited a more than threefold higher cleavage efficacy than its unmodified counterpart. The increased resistance against nuclease degradation is mainly due to terminal phosphorothioate linkages, suggesting that both 5' and 3'-exonucleases are primarily responsible for the nuclear degradation of oligonucleotides.
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Affiliation(s)
- O Heidenreich
- Scripps Research Institute, Department of Molecular and Experimental Medicine, La Jolla, CA 92037, USA
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32
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Design, Synthesis, and Function of Therapeutic Hammerhead Ribozymes. NUCLEIC ACIDS AND MOLECULAR BIOLOGY 1996. [DOI: 10.1007/978-3-642-61202-2_14] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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33
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Beigelman L, Karpeisky A, Matulic-Adamic J, Haeberli P, Sweedler D, Usman N. Synthesis of 2'-modified nucleotides and their incorporation into hammerhead ribozymes. Nucleic Acids Res 1995; 23:4434-42. [PMID: 7501467 PMCID: PMC307401 DOI: 10.1093/nar/23.21.4434] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Several 2'-modified ribonucleoside phosphoramidites have been prepared for structure-activity studies of the hammerhead ribozyme. The aim of these studies was to design and synthesize catalytically active and nuclease-resistant ribozymes. Synthetic schemes for stereoselective synthesis of the R isomer of 2'-deoxy-2'-C-allyl uridine and cytidine phosphoramidites, based on the Keck allylation procedure, were developed. Protection of the 2'-amino group in 2'-deoxy-2'-aminouridine was optimized and a method for the convenient preparation of 5'-O-dimethoxytrityl-2'-deoxy-2'-phthalimidouridine 3'-O-(2-cyanoethyl-N,N-diisopropylphosphoramidite) was developed. During the attempted preparation of the 2'-O-t-butyldimethylsilyl-3'-O-phosphoramidite of arabinouridine a reversed regioselectivity in the silylation reaction, compared with the published procedure, was observed, as well as the unexpected formation of the 2,2'-anhydronucleoside. A possible mechanism for this cyclization is proposed. The synthesis of 2'-deoxy-2'-methylene and 2'-deoxy-2'-difluoromethylene uridine phosphoramidites is described. Based on a '5-ribose' model for essential 2'-hydroxyls in the hammerhead ribozyme these 2'-modified monomers were incorporated at positions U4 and/or U7 of the catalytic core. A number of these ribozymes had almost wild-type catalytic activity and improved stability in human serum, compared with an all-RNA molecule.
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Affiliation(s)
- L Beigelman
- Department of Chemistry and Biochemistry, Ribozyme Pharmaceuticals Inc., Boulder, CO 80301, USA
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34
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Beigelman L, McSwiggen JA, Draper KG, Gonzalez C, Jensen K, Karpeisky AM, Modak AS, Matulic-Adamic J, DiRenzo AB, Haeberli P. Chemical modification of hammerhead ribozymes. Catalytic activity and nuclease resistance. J Biol Chem 1995; 270:25702-8. [PMID: 7592749 DOI: 10.1074/jbc.270.43.25702] [Citation(s) in RCA: 195] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A systematic study of selectively modified, 36-mer hammerhead ribozymes has resulted in the identification of a generic, catalytically active and nuclease stable ribozyme motif containing 5 ribose residues, 29-30 2'-O-Me nucleotides, 1-2 other 2'-modified nucleotides at positions U4 and U7, and a 3'-3'-linked nucleotide "cap." Eight 2'-modified uridine residues were introduced at positions U4 and U7. From the resulting set of ribozymes, several have almost wild-type catalytic activity and significantly improved stability. Specifically, ribozymes containing 2'-NH2 substitutions at U4 and U7, or 2'-C-allyl substitutions at U4, retain most of their catalytic activity when compared to the all-RNA parent. Their serum half-lives were 5-8 h in a variety of biological fluids, including human serum, while the all-RNA parent ribozyme exhibits a stability half-life of only approximately 0.1 min. The addition of a 3'-3'-linked nucleotide "cap" (inverted T) did not affect catalysis but increased the serum half-lives of these two ribozymes to > 260 h at nanomolar concentrations. This represents an overall increase in stability/activity of 53,000-80,000-fold compared to the all-RNA parent ribozyme.
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Affiliation(s)
- L Beigelman
- Department of Chemistry and Biochemistry, Ribozyme Pharmaceuticals Inc., Boulder, Colorado 80301, USA
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35
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Wincott F, DiRenzo A, Shaffer C, Grimm S, Tracz D, Workman C, Sweedler D, Gonzalez C, Scaringe S, Usman N. Synthesis, deprotection, analysis and purification of RNA and ribozymes. Nucleic Acids Res 1995; 23:2677-84. [PMID: 7544462 PMCID: PMC307092 DOI: 10.1093/nar/23.14.2677] [Citation(s) in RCA: 370] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Improvements in the synthesis, deprotection and purification of oligoribonucleotides are described. These advances allow for reduced synthesis and deprotection times, while improving product yield. Coupling times are reduced by half using 5-ethylthio-1H-tetrazole (S-ethyltetrazole) as the activator. Base and 2'-O-t-butyldimethylsilyl deprotection with methylamine (MA) and anhydrous triethylamine/hydrogen fluoride in N-methylpyrrolidinone (TEA.HF/NMP), respectively, requires a fraction of the time necessitated by current standard methods. In addition, the ease of oligoribonucleotide purification and analysis have been significantly enhanced using anion exchange chromatography. These new methods improve the yield and quality of the oligoribonucleotides synthesized. Hammerhead ribozymes synthesized utilizing the described methods exhibited no diminution in catalytic activity.
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Affiliation(s)
- F Wincott
- Department of Chemistry and Biochemistry, Ribozyme Pharmaceuticals Inc., Boulder, CO 80301, USA
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36
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Heidenreich O, Kang SH, Brown DA, Xu X, Swiderski P, Rossi JJ, Eckstein F, Nerenberg M. Ribozyme-mediated RNA degradation in nuclei suspension. Nucleic Acids Res 1995; 23:2223-8. [PMID: 7610051 PMCID: PMC307011 DOI: 10.1093/nar/23.12.2223] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Ribozymes containing 2'-fluoro- and 2'-amino-modified pyrimidine nucleosides in combination with terminal phosphorothioate linkages were targeted against HTLV-I tax RNA. In order to examine the activity of such chemically modified ribozymes in the nuclear environment, they were incubated with nuclei of a Tax-transformed mouse fibroblast cell line. Ribozyme cleavage of tax RNA was analyzed by the RNase protection assay. Comparison of the cleavage of tax RNA isolated nuclei with that of tax RNA present in nuclei suspension revealed a 30 times more efficient cleavage of the latter one. Pre-treatment with proteinase K and SDS abolished the enhancement of the ribozyme-mediated RNA cleavage. Catalytically inactive ribozymes did not yield any cleavage products. These results demonstrate an augmenting effect of nuclear proteins on the ribozyme-mediated RNA cleavage.
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Affiliation(s)
- O Heidenreich
- Scripps Research Institute, Department of Neuropharmacology, La Jolla, CA 92037, USA
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37
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Chapter 30. Catalytic RNA (Ribozymes) as Drugs. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1995. [DOI: 10.1016/s0065-7743(08)60943-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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38
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39
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Grasby JA, Pritchard CE, Gait MJ. Applications of synthetic oligoribonucleotide analogues in studies of RNA structure and function. J CHEM SCI 1994. [DOI: 10.1007/bf02841914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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40
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Breaker RR, Joyce GF. Inventing and improving ribozyme function: rational design versus iterative selection methods. Trends Biotechnol 1994; 12:268-75. [PMID: 7519862 DOI: 10.1016/0167-7799(94)90138-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Two major strategies for generating novel biological catalysts exist. One relies on our knowledge of biopolymer structure and function to aid in the 'rational design' of new enzymes. The other, often called 'irrational design', aims to generate new catalysts, in the absence of detailed physicochemical knowledge, by using selection methods to search a library of molecules for functional variants. Both strategies have been applied, with considerable success, to the remodeling of existing ribozymes and the development of ribozymes with novel catalytic function. The two strategies are by no means mutually exclusive, and are best applied in a complementary fashion to obtain ribozymes with the desired catalytic properties.
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Affiliation(s)
- R R Breaker
- Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037
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41
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Crouch GJ, Eaton BE. Synthesis of 2′-Deoxyuridine Nucleosides with Appended 5-Position Carbonyl Cross-Linking Groups. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/15257779408011867] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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42
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Altmann CR, Solow-Cordero DE, Chamberlin MJ. RNA cleavage and chain elongation by Escherichia coli DNA-dependent RNA polymerase in a binary enzyme.RNA complex. Proc Natl Acad Sci U S A 1994; 91:3784-8. [PMID: 7513426 PMCID: PMC43666 DOI: 10.1073/pnas.91.9.3784] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In the absence of DNA, Escherichia coli RNA polymerase (EC 2.7.7.6) can bind RNA to form an equimolar binary complex with the concomitant release of the sigma factor. We show now that E. coli RNA polymerase binds at a region near the 3' terminus of the RNA and that an RNA in such RNA.RNA polymerase complexes undergoes reactions previously thought to be unique to nascent RNA in ternary complexes with DNA. These include GreA/GreB-dependent cleavage of the RNA and elongation by 3'-terminal addition of NMP from NTP. Both of these reactions are inhibited by rifampicin. Hence, by several criteria, the RNA in binary complexes is bound to the polymerase in a manner quite similar to that in ternary complexes. These findings can be explained by a model for the RNA polymerase ternary complex in which the RNA is bound at the 3' terminus through two protein binding sites located up to 10 nt apart. In this model, the stability of RNA binding to the polymerase in the ternary complex is due primarily to its interaction with the protein.
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Affiliation(s)
- C R Altmann
- Department of Molecular and Cell Biology, University of California, Berkeley 94720
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43
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Abstract
Molecular modelling has been used to probe the conformational preferences of double stranded DNA-RNA hybrids. As might be expected, the sugars of the DNA strand have higher conformational flexibility, but, for the majority of the repetitive sequences studied, these sugars prefer a C2-endo pucker, while ribose sugars uniformly adopt a C3-endo pucker. This gives rise to a strongly heteronomous duplex conformation. One exception to this rule involves the thymidine strand of poly(dT).poly(rA), which marginally prefers a C3-endo pucker. Our study further indicates that the DNA strands of the hybrids favour backbone torsions in the canonical B domain, rather than the modified values proposed on the basis of fibre diffraction studies. Backbone conformational transitions can nevertheless be induced leading to an alpha gamma-flip (alpha:gamma, g-/g(+)-->t/t) or to the alpha beta gamma-flip form proposed from fibre studies (alpha:beta:gamma, g-/t/g(+)-->t/g+/t). The latter transition is also found to be linked to BI-->BII transitions (epsilon:zeta, t/g(-)-->g-/t).
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Affiliation(s)
- S R Sanghani
- Laboratoire de Biochimie Théorique, CNRS URA 77, Institut de Biologie Physico-Chimique, Paris, France
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44
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Grasby JA, Gait MJ. Synthetic oligoribonucleotides carrying site-specific modifications for RNA structure-function analysis. Biochimie 1994; 76:1223-34. [PMID: 7538326 DOI: 10.1016/0300-9084(94)90053-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Synthetic oligoribonucleotides have become increasingly valuable in studies of RNA structure and function. A range of nucleotide analogues is available which carry modifications in the base, sugar or phosphate moieties. Such analogues have been incorporated into synthetic RNA structures to eliminate or alter individual functional groups in the RNA which potentially can take part in hydrogen-bonding or other non-covalent interactions. Comparisons of the properties of the modified RNAs with unmodified RNA models allow conclusions to be drawn concerning the importance or otherwise of specific functional groups within the RNA. These methods have been applied to studies of RNA interactions with proteins, RNA catalysis and RNA structure.
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Affiliation(s)
- J A Grasby
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK
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46
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Bratty J, Chartrand P, Ferbeyre G, Cedergren R. The hammerhead RNA domain, a model ribozyme. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1216:345-59. [PMID: 7505618 DOI: 10.1016/0167-4781(93)90001-t] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- J Bratty
- Département de Biochimie, Université de Montréal, Québec, Canada
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47
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Nolan JM, Burke DH, Pace NR. Circularly permuted tRNAs as specific photoaffinity probes of ribonuclease P RNA structure. Science 1993; 261:762-5. [PMID: 7688143 DOI: 10.1126/science.7688143] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Regions of Escherichia coli ribonuclease P (RNase P) RNA in proximity to a bound transfer RNA (tRNA) substrate were mapped by photoaffinity. A photoaffinity cross-linking reagent was introduced at specific sites in the interior of the native tRNA structure by modification of the 5' ends of circularly permuted tRNAs (cptRNAs). The polymerase chain reaction was used for the production of cptRNA templates. After the amplification of a segment of a tandemly duplicated tRNA gene, the cptRNA gene was transcribed in vitro to produce cptRNA. Modified cptRNAs were cross-linked to RNase P RNA, and the conjugation sites in RNase P RNA were determined by primer extension. These sites occur in phylogenetically conserved structures and sequences and identify regions of the ribozyme that form part of the tRNA binding site. The use of circularly permuted molecules to position specific modifications is applicable to the study of many inter- and intramolecular interactions.
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Affiliation(s)
- J M Nolan
- Department of Biology, Indiana University, Bloomington 47405
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48
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An indexed bibliography of antisense literature, 1992. ANTISENSE RESEARCH AND DEVELOPMENT 1993; 3:95-153. [PMID: 8495109 DOI: 10.1089/ard.1993.3.95] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Usman N, Egli M, Rich A. Large scale chemical synthesis, purification and crystallization of RNA-DNA chimeras. Nucleic Acids Res 1992; 20:6695-9. [PMID: 1282704 PMCID: PMC334588 DOI: 10.1093/nar/20.24.6695] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
RNA-DNA chimeras, in which both DNA and RNA monomers are site-specifically substituted in the same strand, may be prepared only by chemical synthesis. Biochemical studies have revealed a number of surprising and subtle effects resulting from the insertion of either a ribonucleotide into a DNA strand or a deoxyribonucleotide into an RNA strand. The availability of large quantities of these chimeras allows for their crystallization and subsequent x-ray structure determination. We describe a flexible and efficient method for the large-scale preparation of these compounds, their purification, and their crystallization. The methodology is based on a combination of existing DNA phosphoramidite synthons and those recently introduced for the preparation of biochemically active RNA1. We demonstrate that these two different synthons are compatible, produce large quantities of nucleic acid needed for physical studies, and that high resolution diffraction quality crystals may be grown from these chimeras. Of the duplex chimeras synthesized and crystallized, [r(G)d(CGTATACGC)]2, [d(GCGT)r(A)d(TACGC)]2 and [r(GCG)d(TATACCC) + d(GGGTATACGC)] form A-helices and d(CG)r(CG)d(CG)]2 forms a left-handed Z-helix.
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Affiliation(s)
- N Usman
- Department of Biology, Massachusetts Institute of Technology, Cambridge 02139
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