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Cui X, Fan J, Lyu Y, Zhou X, Meng Q, Zhang C. Quasi-intrinsic thiobase derivatives as potential targeted photosensitizers in two-photon photodynamic therapy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 316:124311. [PMID: 38663131 DOI: 10.1016/j.saa.2024.124311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 05/15/2024]
Abstract
In this study, a set of potential quasi-intrinsic photosensitizers for two-photon photodynamic therapy (PDT) are proposed based on the unnatural 2-amino-8-(1'-β-ᴅ-2'-deoxyribofuranosyl)-imidazo[1,2-ɑ]-1,3,5-triazin-4(8H)-one (P), which is paired with the 6-amino-5-nitro-3-(1'-β-ᴅ-2'-deoxyribofuranosyl)-2(1H)-pyridone (Z) and can specifically recognize breast and liver cancer cells. Herein, the effects of sulfur substitution and electron-donating/electron-withdrawing groups on the photophysical properties in aqueous solution are systematically investigated. The one- and two-photon absorption spectra evidence that the modifications could result in red-shifted absorption wavelength and large two-photon absorption cross-section, which contributes to selective excitation and provides effective PDT for deep-seated tissues. To ensure the efficient triplet state population, the singlet-triplet energy gaps and spin-orbit coupling constants were examined, which is responsible for a rapid intersystem crossing rate. Furthermore, these thiobase derivatives are characterized by the long-lived T1 state and the large energy gap for radiationless transition to ensure the generation of cytotoxic singlet oxygen.
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Affiliation(s)
- Xixi Cui
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Jianzhong Fan
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Yongkang Lyu
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Xucong Zhou
- School of Basic Medical Sciences, Shandong Second Medical University, Weifang 261053, PR China
| | - Qingtian Meng
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China.
| | - Changzhe Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China.
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Cui X, Yuan H, Chen X, Meng Q, Zhang C. Newly Designed Quasi-intrinsic Photosensitizers for Fluorescence Image-Guided Two-Photon Photodynamic Therapy with Type I/II Photoreactions. J Med Chem 2024; 67:8902-8912. [PMID: 38815214 DOI: 10.1021/acs.jmedchem.4c00191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
In this work, a set of quasi-intrinsic photosensitizers are theoretically proposed based on the 2-amino-8-(1'-β-d-2'-deoxyribofuranosyl)-imidazo[1,2-α]-1,3,5-triazin-4(8H)-one (P), which could pair with the 6-amino-5-nitro-3-(1'-β-d-2'-deoxyribofuranosyl)-2(1H)-pyridone (Z) and keep the essential structural characters of nucleic acid. It is revealed that the ring expansion and electron-donating/electron-withdrawing substitution bring enhanced two-photon absorption and bright photoluminescence of these monomers, thereby facilitating the selective excitation and tumor localization through fluorescence imaging. However, instead of undergoing radiative transition (S1 → S0), the base pairing induced fluorescence quenching and rapid intersystem crossing (S1 → Tn) are observed and characterized by the reduced singlet-triplet energy gaps and large spin-orbit coupling values. To ensure the phototherapeutic properties of the considered base pairs in long-lived T1 state, we examined the vertical electron affinity as well as vertical ionization potential for production of superoxide anions via Type I photoreaction, and their required T1 energy (0.98 eV) to generate singlet oxygen 1O2 via Type II mechanism.
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Affiliation(s)
- Xixi Cui
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Hongxiu Yuan
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Xiaolin Chen
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Qingtian Meng
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Changzhe Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
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Sett A, Gadewar M, Babu MA, Panja A, Sachdeva P, Almutary AG, Upadhye V, Jha SK, Jha NK. Orchestration and theranostic applications of synthetic genome with Hachimoji bases/building blocks. Chem Biol Drug Des 2024; 103:e14378. [PMID: 38230795 DOI: 10.1111/cbdd.14378] [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] [Received: 03/26/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 01/18/2024]
Abstract
Synthetic genomics is a novel field of chemical biology where the chemically modified genetic alphabets have been considered in central dogma of life. Tweaking of chemical compositions of natural nucleotide bases could be developed as novel building blocks of DNA/RNA. The modified bases (dP, dZ, dS, and dB etc.) have been demonstrated to be adaptable for replication, transcription and follow Darwinism law of evolution. With advancement of chemical biology especially nucleotide chemistry, synthetic genetic codes have been discovered and Hachimoji nucleotides are the most important and significant one among them. These additional nucleotide bases can form orthogonal base-pairing, and also follow Darwinian evolution and other structural features. In the Hachimoji base pairing, synthetic building blocks are formed using eight modified nucleotide (DNA/RNA) letters (hence the name "Hachimoji"). Their structural conformations, like polyelectrolyte backbones and stereo-regular building blocks favor thermodynamic stability and confirm Schrodinger aperiodic crystal. From the structural genomics aspect, these synthetic bases could be incorporated into the central dogma of life. Researchers have shown Hachimoji building blocks were transcribed to its RNA counterpart as a functional fluorescent Hachimoji aptamer. Apart from several unnatural nucleotide base pairs maneuvered into its in vitro and in vivo applications, this review describes future perspective towards the development and therapeutic utilization of the genetic codes, a primary objective of synthetic and chemical biology.
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Affiliation(s)
- Arghya Sett
- ERIN Department, Luxembourg Institute of Science and Technology, 5 Av. des Hauts-Fourneaux, Belval, 4362, Esch, Luxembourg
| | - Manoj Gadewar
- Department of Pharmacology, School of Medical and Allied Sciences, K R Mangalam University, Gurgaon, India
| | - M Arockia Babu
- Institute of Pharmaceutical Research, GLA University, Mathura, India
| | | | | | - Abdulmajeed G Almutary
- Department of Biomedical Sciences, College of Health Sciences, Abu Dhabi University, Abu Dhabi, United Arab Emirates
| | - Vijay Upadhye
- Centre of Research for Development (CR4D) and Department of Microbiology, Parul University, Vadodara, Gujarat, India
| | - Saurabh Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Niraj Kumar Jha
- Centre for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India
- Centre of Research Impact and Outreach, Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, India
- School of Bioengineering & Biosciences, Lovely Professional University, Phagwara, 144411, India
- Department of Biotechnology Engineering and Food Technology, Chandigarh University, Mohali, 140413, India
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Jena NR, Shukla PK. Structure and stability of different triplets involving artificial nucleobases: clues for the formation of semisynthetic triple helical DNA. Sci Rep 2023; 13:19246. [PMID: 37935822 PMCID: PMC10630353 DOI: 10.1038/s41598-023-46572-4] [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: 08/21/2023] [Accepted: 11/02/2023] [Indexed: 11/09/2023] Open
Abstract
A triple helical DNA can control gene expression, help in homologous recombination, induce mutations to facilitate DNA repair mechanisms, suppress oncogene formations, etc. However, the structure and function of semisynthetic triple helical DNA are not known. To understand this, various triplets formed between eight artificial nucleobases (P, Z, J, V, B, S, X, and K) and four natural DNA bases (G, C, A, and T) are studied herein by employing a reliable density functional theoretic (DFT) method. Initially, the triple helix-forming artificial nucleobases interacted with the duplex DNA containing GC and AT base pairs, and subsequently, triple helix-forming natural bases (G and C) interacted with artificial duplex DNA containing PZ, JV, BS, and XK base pairs. Among the different triplets formed in the first category, the C-JV triplet is found to be the most stable with a binding energy of about - 31 kcal/mol. Similarly, among the second category of triplets, the Z-GC and V-GC triplets are the most stable. Interestingly, Z-GC and V-GC are found to be isoenergetic with a binding energy of about - 30 kcal/mol. The C-JV, and Z-GC or V-GC triplets are about 12-14 kcal/mol more stable than the JV and GC base pairs respectively. Microsolvation of these triplets in 5 explicit water molecules further enhanced their stability by 16-21 kcal/mol. These results along with the consecutive stacking of the C-JV triplet (C-JV/C-JV) data indicate that the synthetic nucleobases can form stable semisynthetic triple helical DNA. However, consideration of a full-length DNA containing one or more semisynthetic bases or base pairs is necessary to understand the formation of semisynthetic DNA in living cells.
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Affiliation(s)
- N R Jena
- Discipline of Natural Sciences, Indian Institute of Information Technology, Design, and Manufacturing, Dumna Airport Road, Khamaria, Jabalpur, 482005, India.
| | - P K Shukla
- Department of Physics, Assam University, Silchar, Assam, 788 011, India
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Cui X, Zhao Y, Li Z, Meng Q, Zhang C. Proton Transfer and Nitro Rotation Tuned Photoisomerization of Artificial Base Pair-ZP. Front Chem 2020; 8:605117. [PMID: 33330400 PMCID: PMC7734142 DOI: 10.3389/fchem.2020.605117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/09/2020] [Indexed: 11/13/2022] Open
Abstract
Recently, the successful incorporation of artificial base pairs in genetics has made a significant progress in synthetic biology. The present work reports the proton transfer and photoisomerization of unnatural base pair ZP, which is synthesized from the pyrimidine analog 6-amino-5-nitro-3-(1-β-D-2'-deoxyribo-furanosyl)-2 (1H)-pyridone (Z) and paired with its Watson-Crick complement, the purine analog 2-amino-8-(1'-β-D-2'- deoxyribofuranosyl)-imidazo[1,2-a]-1,3,5-triazin-4(8H)-one (P). To explain the mechanism of proton transfer process, we constructed the relaxed potential energy surfaces (PESs) linking the different tautomers in both gas phase and solution. Our results show that the double proton transfer in the gas phase occurs in a concerted way both in S0 and S1 states, while the stepwise mechanism becomes more favorable in solution. The solvent effect can promote the single proton transfer, which undergoes a lower energy barrier in S1 state due to the strengthened hydrogen bond. In contrast to the excited state ultrafast deactivation process of the natural bases, there is no conical intersection between S0 and S1 states along the proton transfer coordinate to activate the decay mechanism in ZP. Of particular relevance to the photophysical properties, charge-transfer character is obviously related to the nitro rotation in S1 state. We characterized the molecular vibration effect on the electronic properties, which reveals the electronic excitation can be tuned by the rotation-induced structural distortion accompanied with the electron localization on nitro group.
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Affiliation(s)
- Xixi Cui
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
| | - Yu Zhao
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
| | - Zhibing Li
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
| | - Qingtian Meng
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
| | - Changzhe Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, China
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Ouaray Z, Benner SA, Georgiadis MM, Richards NGJ. Building better polymerases: Engineering the replication of expanded genetic alphabets. J Biol Chem 2020; 295:17046-17059. [PMID: 33004440 PMCID: PMC7863901 DOI: 10.1074/jbc.rev120.013745] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
DNA polymerases are today used throughout scientific research, biotechnology, and medicine, in part for their ability to interact with unnatural forms of DNA created by synthetic biologists. Here especially, natural DNA polymerases often do not have the "performance specifications" needed for transformative technologies. This creates a need for science-guided rational (or semi-rational) engineering to identify variants that replicate unnatural base pairs (UBPs), unnatural backbones, tags, or other evolutionarily novel features of unnatural DNA. In this review, we provide a brief overview of the chemistry and properties of replicative DNA polymerases and their evolved variants, focusing on the Klenow fragment of Taq DNA polymerase (Klentaq). We describe comparative structural, enzymatic, and molecular dynamics studies of WT and Klentaq variants, complexed with natural or noncanonical substrates. Combining these methods provides insight into how specific amino acid substitutions distant from the active site in a Klentaq DNA polymerase variant (ZP Klentaq) contribute to its ability to replicate UBPs with improved efficiency compared with Klentaq. This approach can therefore serve to guide any future rational engineering of replicative DNA polymerases.
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Affiliation(s)
- Zahra Ouaray
- School of Chemistry, Cardiff University, Park Place, Cardiff, United Kingdom
| | - Steven A Benner
- Foundation for Applied Molecular Evolution, Alachua, Florida, USA
| | - Millie M Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
| | - Nigel G J Richards
- School of Chemistry, Cardiff University, Park Place, Cardiff, United Kingdom; Foundation for Applied Molecular Evolution, Alachua, Florida, USA.
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Ledbetter MP, Craig JM, Karadeema RJ, Noakes MT, Kim HC, Abell SJ, Huang JR, Anderson BA, Krishnamurthy R, Gundlach JH, Romesberg FE. Nanopore Sequencing of an Expanded Genetic Alphabet Reveals High-Fidelity Replication of a Predominantly Hydrophobic Unnatural Base Pair. J Am Chem Soc 2020; 142:2110-2114. [PMID: 31985216 DOI: 10.1021/jacs.9b09808] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Unnatural base pairs (UBPs) have been developed and used for a variety of in vitro applications as well as for the engineering of semisynthetic organisms (SSOs) that store and retrieve increased information. However, these applications are limited by the availability of methods to rapidly and accurately determine the sequence of unnatural DNA. Here we report the development and application of the MspA nanopore to sequence DNA containing the dTPT3-dNaM UBP. Analysis of two sequence contexts reveals that DNA containing the UBP is replicated with an efficiency and fidelity similar to that of natural DNA and sufficient for use as the basis of an SSO that produces proteins with noncanonical amino acids.
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Affiliation(s)
- Michael P Ledbetter
- Department of Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Jonathan M Craig
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Rebekah J Karadeema
- Department of Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Matthew T Noakes
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Hwanhee C Kim
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Sarah J Abell
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Jesse R Huang
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Brooke A Anderson
- Department of Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
| | | | - Jens H Gundlach
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Floyd E Romesberg
- Department of Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
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Jakubovska J, Tauraitė D, Meškys R. Transient N 4 -Acyl-DNA Protection against Cleavage by Restriction Endonucleases. Chembiochem 2019; 20:2504-2512. [PMID: 31090133 DOI: 10.1002/cbic.201900280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Indexed: 01/06/2023]
Abstract
A set of five N4 -acyl-modified 2'-deoxycytidine 5'-triphosphates were incorporated into modified DNA by using phi29 DNA polymerase, and cleavage by selected restriction endonucleases was studied. Modified DNA containing N4 -acyl functional groups in either one or both strands of a DNA molecule was resistant to the majority of restriction enzymes tested, whereas modifications outside of the recognition sequences were well tolerated. The N4 -acylated cytidine derivatives were subjected to competitive nucleotide incorporation by using phi29 DNA polymerase, showing that a high-fidelity phi29 DNA polymerase efficiently used the modified analogues in the presence of its natural counterpart. These N4 modifications were also demonstrated to be easily removed in an aqueous ethanolamine solution, in which all steps, including primer extension, demodification, and cleavage by restriction endonuclease, could be performed in a one-pot procedure that eliminated additional purification stages. It is suggested that N4 -modified nucleotides are promising building blocks for a programmable; transient; and, most importantly, straightforward DNA protection against specific endonucleases.
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Affiliation(s)
- Jevgenija Jakubovska
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257, Vilnius, Lithuania
| | - Daiva Tauraitė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257, Vilnius, Lithuania
| | - Rolandas Meškys
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257, Vilnius, Lithuania
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Gao W, Cho E, Liu Y, Lu Y. Advances and Challenges in Cell-Free Incorporation of Unnatural Amino Acids Into Proteins. Front Pharmacol 2019; 10:611. [PMID: 31191324 PMCID: PMC6549004 DOI: 10.3389/fphar.2019.00611] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/15/2019] [Indexed: 12/17/2022] Open
Abstract
Incorporation of unnatural amino acids (UNAAs) into proteins currently is an active biological research area for various fundamental and applied science. In this context, cell-free synthetic biology (CFSB) has been developed and recognized as a robust testing and biomanufacturing platform for highly efficient UNAA incorporation. It enables the orchestration of unnatural biological machinery toward an exclusive user-defined objective of unnatural protein synthesis. This review aims to overview the principles of cell-free unnatural protein synthesis (CFUPS) systems, their advantages, different UNAA incorporation approaches, and recent achievements. These have catalyzed cutting-edge research and diverse emerging applications. Especially, present challenges and future trends are focused and discussed. With the development of CFSB and the fusion with other advanced next-generation technologies, CFUPS systems would explicitly deliver their values for biopharmaceutical applications.
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Affiliation(s)
- Wei Gao
- Department of Chemical Engineering, Tsinghua University, Beijing, China
- College of Life Science, Shenyang Normal University, Shenyang, China
| | - Eunhee Cho
- Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Yingying Liu
- Department of Chemical Engineering, Tsinghua University, Beijing, China
- College of Life Science, Shenyang Normal University, Shenyang, China
| | - Yuan Lu
- Department of Chemical Engineering, Tsinghua University, Beijing, China
- Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
- Key Lab of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
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Whitford CM, Dymek S, Kerkhoff D, März C, Schmidt O, Edich M, Droste J, Pucker B, Rückert C, Kalinowski J. Auxotrophy to Xeno-DNA: an exploration of combinatorial mechanisms for a high-fidelity biosafety system for synthetic biology applications. J Biol Eng 2018; 12:13. [PMID: 30123321 PMCID: PMC6090650 DOI: 10.1186/s13036-018-0105-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/25/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Biosafety is a key aspect in the international Genetically Engineered Machine (iGEM) competition, which offers student teams an amazing opportunity to pursue their own research projects in the field of Synthetic Biology. iGEM projects often involve the creation of genetically engineered bacterial strains. To minimize the risks associated with bacterial release, a variety of biosafety systems were constructed, either to prevent survival of bacteria outside the lab or to hinder horizontal or vertical gene transfer. MAIN BODY Physical containment methods such as bioreactors or microencapsulation are considered the first safety level. Additionally, various systems involving auxotrophies for both natural and synthetic compounds have been utilized by iGEM teams in recent years. Combinatorial systems comprising multiple auxotrophies have been shown to reduced escape frequencies below the detection limit. Furthermore, a number of natural toxin-antitoxin systems can be deployed to kill cells under certain conditions. Additionally, parts of naturally occurring toxin-antitoxin systems can be used for the construction of 'kill switches' controlled by synthetic regulatory modules, allowing control of cell survival. Kill switches prevent cell survival but do not completely degrade nucleic acids. To avoid horizontal gene transfer, multiple mechanisms to cleave nucleic acids can be employed, resulting in 'self-destruction' of cells. Changes in light or temperature conditions are powerful regulators of gene expression and could serve as triggers for kill switches or self-destruction systems. Xenobiology-based containment uses applications of Xeno-DNA, recoded codons and non-canonical amino acids to nullify the genetic information of constructed cells for wild type organisms. A 'minimal genome' approach brings the opportunity to reduce the genome of a cell to only genes necessary for survival under lab conditions. Such cells are unlikely to survive in the natural environment and are thus considered safe hosts. If suitable for the desired application, a shift to cell-free systems based on Xeno-DNA may represent the ultimate biosafety system. CONCLUSION Here we describe different containment approaches in synthetic biology, ranging from auxotrophies to minimal genomes, which can be combined to significantly improve reliability. Since the iGEM competition greatly increases the number of people involved in synthetic biology, we will focus especially on biosafety systems developed and applied in the context of the iGEM competition.
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Affiliation(s)
| | - Saskia Dymek
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Denise Kerkhoff
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Camilla März
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Olga Schmidt
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Maximilian Edich
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Julian Droste
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Boas Pucker
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Present address: Evolution and Diversity, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Christian Rückert
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
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Biondi E, Benner SA. Artificially Expanded Genetic Information Systems for New Aptamer Technologies. Biomedicines 2018; 6:E53. [PMID: 29747381 PMCID: PMC6027400 DOI: 10.3390/biomedicines6020053] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/04/2018] [Accepted: 05/06/2018] [Indexed: 01/04/2023] Open
Abstract
Directed evolution was first applied to diverse libraries of DNA and RNA molecules a quarter century ago in the hope of gaining technology that would allow the creation of receptors, ligands, and catalysts on demand. Despite isolated successes, the outputs of this technology have been somewhat disappointing, perhaps because the four building blocks of standard DNA and RNA have too little functionality to have versatile binding properties, and offer too little information density to fold unambiguously. This review covers the recent literature that seeks to create an improved platform to support laboratory Darwinism, one based on an artificially expanded genetic information system (AEGIS) that adds independently replicating nucleotide “letters” to the evolving “alphabet”.
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Affiliation(s)
- Elisa Biondi
- Foundation for Applied Molecular Evolution, Alachua, FL 32615, USA.
- Firebird Biomolecular Sciences, LLC, Alachua, FL 32615, USA.
| | - Steven A Benner
- Foundation for Applied Molecular Evolution, Alachua, FL 32615, USA.
- Firebird Biomolecular Sciences, LLC, Alachua, FL 32615, USA.
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12
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Wang X, Hoshika S, Peterson RJ, Kim MJ, Benner SA, Kahn JD. Biophysics of Artificially Expanded Genetic Information Systems. Thermodynamics of DNA Duplexes Containing Matches and Mismatches Involving 2-Amino-3-nitropyridin-6-one (Z) and Imidazo[1,2-a]-1,3,5-triazin-4(8H)one (P). ACS Synth Biol 2017; 6:782-792. [PMID: 28094993 DOI: 10.1021/acssynbio.6b00224] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Synthetic nucleobases presenting non-Watson-Crick arrangements of hydrogen bond donor and acceptor groups can form additional nucleotide pairs that stabilize duplex DNA independent of the standard A:T and G:C pairs. The pair between 2-amino-3-nitropyridin-6-one 2'-deoxyriboside (presenting a {donor-donor-acceptor} hydrogen bonding pattern on the Watson-Crick face of the small component, trivially designated Z) and imidazo[1,2-a]-1,3,5-triazin-4(8H)one 2'-deoxyriboside (presenting an {acceptor-acceptor-donor} hydrogen bonding pattern on the large component, trivially designated P) is one of these extra pairs for which a substantial amount of molecular biology has been developed. Here, we report the results of UV absorbance melting measurements and determine the energetics of binding of DNA strands containing Z and P to give short duplexes containing Z:P pairs as well as various mismatches comprising Z and P. All measurements were done at 1 M NaCl in buffer (10 mM Na cacodylate, 0.5 mM EDTA, pH 7.0). Thermodynamic parameters (ΔH°, ΔS°, and ΔG°37) for oligonucleotide hybridization were extracted. Consistent with the Watson-Crick model that considers both geometric and hydrogen bonding complementarity, the Z:P pair was found to contribute more to duplex stability than any mismatches involving either nonstandard nucleotide. Further, the Z:P pair is more stable than a C:G pair. The Z:G pair was found to be the most stable mismatch, forming either a deprotonated mismatched pair or a wobble base pair analogous to the stable T:G mismatch. The C:P pair is less stable, perhaps analogous to the wobble pair observed for C:O6-methyl-G, in which the pyrimidine is displaced into the minor groove. The Z:A and T:P mismatches are much less stable. Parameters for predicting the thermodynamics of oligonucleotides containing Z and P bases are provided. This represents the first case where this has been done for a synthetic genetic system.
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Affiliation(s)
- Xiaoyu Wang
- Department
of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Shuichi Hoshika
- Foundation for Applied Molecular Evolution, 13709 Progress Boulevard, No. 7, Alachua, Florida 32615, United States
| | - Raymond J. Peterson
- Celadon Laboratories, 6525 Belcrest
Road, Hyattsville, Maryland 20782, United States
| | - Myong-Jung Kim
- Foundation for Applied Molecular Evolution, 13709 Progress Boulevard, No. 7, Alachua, Florida 32615, United States
| | - Steven A. Benner
- Foundation for Applied Molecular Evolution, 13709 Progress Boulevard, No. 7, Alachua, Florida 32615, United States
- Firebird Biomolecular Sciences LLC, 13709 Progress Boulevard, No. 17, Alachua, Florida 32615, United States
| | - Jason D. Kahn
- Department
of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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13
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Molt RW, Georgiadis MM, Richards NG. Consecutive non-natural PZ nucleobase pairs in DNA impact helical structure as seen in 50 μs molecular dynamics simulations. Nucleic Acids Res 2017; 45:3643-3653. [PMID: 28334863 PMCID: PMC5397145 DOI: 10.1093/nar/gkx144] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/12/2017] [Accepted: 02/24/2017] [Indexed: 12/25/2022] Open
Abstract
Z Little is known about the influence of multiple consecutive 'non-standard' ( , 6-amino-5-nitro-2(1H)-pyridone, and , 2-amino-imidazo[1,2-a]-1,3,5-triazin-4(8H)-one) nucleobase pairs on the structural parameters of duplex DNA. nucleobase pairs follow standard rules for Watson-Crick base pairing but have rearranged hydrogen bonding donor and acceptor groups. Using the X-ray crystal structure as a starting point, we have modeled the motions of a DNA duplex built from a self-complementary oligonucleotide (5΄-CTTATPPPZZZATAAG-3΄) in water over a period of 50 μs and calculated DNA local parameters, step parameters, helix parameters, and major/minor groove widths to examine how the presence of multiple, consecutive nucleobase pairs might impact helical structure. In these simulations, the -containing DNA duplex exhibits a significantly wider major groove and greater average values of stagger, slide, rise, twist and h-rise than observed for a 'control' oligonucleotide in which nucleobase pairs are replaced by . The molecular origins of these structural changes are likely associated with at least two differences between and . First, the electrostatic properties of differ from in terms of density distribution and dipole moment. Second, differences are seen in the base stacking of pairs in dinucleotide steps, arising from energetically favorable stacking of the nitro group in with π-electrons of the adjacent base.
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Affiliation(s)
- Robert W. Molt
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
- ENSCO, Inc., 4849 North Wickham Road, Melbourne, FL 32940, USA
| | - Millie M. Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
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14
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Biological phosphorylation of an Unnatural Base Pair (UBP) using a Drosophila melanogaster deoxynucleoside kinase (DmdNK) mutant. PLoS One 2017; 12:e0174163. [PMID: 28323896 PMCID: PMC5360312 DOI: 10.1371/journal.pone.0174163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/03/2017] [Indexed: 11/23/2022] Open
Abstract
One research goal for unnatural base pair (UBP) is to replicate, transcribe and translate them in vivo. Accordingly, the corresponding unnatural nucleoside triphosphates must be available at sufficient concentrations within the cell. To achieve this goal, the unnatural nucleoside analogues must be phosphorylated to the corresponding nucleoside triphosphates by a cascade of three kinases. The first step is the monophosphorylation of unnatural deoxynucleoside catalyzed by deoxynucleoside kinases (dNK), which is generally considered the rate limiting step because of the high specificity of dNKs. Here, we applied a Drosophila melanogaster deoxyribonucleoside kinase (DmdNK) to the phosphorylation of an UBP (a pyrimidine analogue (6-amino-5-nitro-3-(1’-b-d-2’-deoxyribofuranosyl)-2(1H)-pyridone, Z) and its complementary purine analogue (2-amino-8-(1’-b-d-2’-deoxyribofuranosyl)-imidazo[1,2-a]-1,3,5-triazin-4(8H)-one, P). The results showed that DmdNK could efficiently phosphorylate only the dP nucleoside. To improve the catalytic efficiency, a DmdNK-Q81E mutant was created based on rational design and structural analyses. This mutant could efficiently phosphorylate both dZ and dP nucleoside. Structural modeling indicated that the increased efficiency of dZ phosphorylation by the DmdNK-Q81E mutant might be related to the three additional hydrogen bonds formed between E81 and the dZ base. Overall, this study provides a groundwork for the biological phosphorylation and synthesis of unnatural base pair in vivo.
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15
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Torres L, Krüger A, Csibra E, Gianni E, Pinheiro VB. Synthetic biology approaches to biological containment: pre-emptively tackling potential risks. Essays Biochem 2016; 60:393-410. [PMID: 27903826 PMCID: PMC5264511 DOI: 10.1042/ebc20160013] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/21/2016] [Accepted: 10/24/2016] [Indexed: 12/29/2022]
Abstract
Biocontainment comprises any strategy applied to ensure that harmful organisms are confined to controlled laboratory conditions and not allowed to escape into the environment. Genetically engineered microorganisms (GEMs), regardless of the nature of the modification and how it was established, have potential human or ecological impact if accidentally leaked or voluntarily released into a natural setting. Although all evidence to date is that GEMs are unable to compete in the environment, the power of synthetic biology to rewrite life requires a pre-emptive strategy to tackle possible unknown risks. Physical containment barriers have proven effective but a number of strategies have been developed to further strengthen biocontainment. Research on complex genetic circuits, lethal genes, alternative nucleic acids, genome recoding and synthetic auxotrophies aim to design more effective routes towards biocontainment. Here, we describe recent advances in synthetic biology that contribute to the ongoing efforts to develop new and improved genetic, semantic, metabolic and mechanistic plans for the containment of GEMs.
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Affiliation(s)
- Leticia Torres
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, U.K.
| | - Antje Krüger
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, U.K
| | - Eszter Csibra
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, U.K
| | - Edoardo Gianni
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, U.K
| | - Vitor B Pinheiro
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, U.K.
- Birkbeck, Department of Biological Sciences, University of London, Malet Street, WC1E 7HX, U.K
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16
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Benner SA, Karalkar NB, Hoshika S, Laos R, Shaw RW, Matsuura M, Fajardo D, Moussatche P. Alternative Watson-Crick Synthetic Genetic Systems. Cold Spring Harb Perspect Biol 2016; 8:a023770. [PMID: 27663774 PMCID: PMC5088529 DOI: 10.1101/cshperspect.a023770] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In its "grand challenge" format in chemistry, "synthesis" as an activity sets out a goal that is substantially beyond current theoretical and technological capabilities. In pursuit of this goal, scientists are forced across uncharted territory, where they must answer unscripted questions and solve unscripted problems, creating new theories and new technologies in ways that would not be created by hypothesis-directed research. Thus, synthesis drives discovery and paradigm changes in ways that analysis cannot. Described here are the products that have arisen so far through the pursuit of one grand challenge in synthetic biology: Recreate the genetics, catalysis, evolution, and adaptation that we value in life, but using genetic and catalytic biopolymers different from those that have been delivered to us by natural history on Earth. The outcomes in technology include new diagnostic tools that have helped personalize the care of hundreds of thousands of patients worldwide. In science, the effort has generated a fundamentally different view of DNA, RNA, and how they work.
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Affiliation(s)
- Steven A Benner
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Nilesh B Karalkar
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Shuichi Hoshika
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Roberto Laos
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Ryan W Shaw
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Mariko Matsuura
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Diego Fajardo
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
| | - Patricia Moussatche
- The Westheimer Institute for Science and Technology, The Foundation for Applied Molecular Evolution, Alachua, Florida 32615
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17
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Kielkowski P, Fanfrlík J, Hocek M. 7-Aryl-7-deazaadenine 2′-Deoxyribonucleoside Triphosphates (dNTPs): Better Substrates for DNA Polymerases than dATP in Competitive Incorporations. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201404742] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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18
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Kielkowski P, Fanfrlík J, Hocek M. 7-Aryl-7-deazaadenine 2'-deoxyribonucleoside triphosphates (dNTPs): better substrates for DNA polymerases than dATP in competitive incorporations. Angew Chem Int Ed Engl 2014; 53:7552-5. [PMID: 24890276 DOI: 10.1002/anie.201404742] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Indexed: 01/31/2023]
Abstract
A series of 7-substituted 7-deazaadenine and 5-substituted cytosine 2'-deoxyribonucleoside triphosphates (dNTPs) were tested for their competitive incorporations (in the presence of dATP and dCTP) into DNA by several DNA polymerases by using analysis based on cleavage by restriction endonucleases. 7-Aryl-7-deazaadenine dNTPs were more efficient substrates than dATP because of their higher affinity for the active site of the enzyme, as proved by kinetic measurements and calculations.
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Affiliation(s)
- Pavel Kielkowski
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Gilead Sciences & IOCB Research Center, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic) http://www.uochb.cas.cz/hocekgroup
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19
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In vitro selection with artificial expanded genetic information systems. Proc Natl Acad Sci U S A 2013; 111:1449-54. [PMID: 24379378 DOI: 10.1073/pnas.1311778111] [Citation(s) in RCA: 233] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Artificially expanded genetic information systems (AEGISs) are unnatural forms of DNA that increase the number of independently replicating nucleotide building blocks. To do this, AEGIS pairs are joined by different arrangements of hydrogen bond donor and acceptor groups, all while retaining their Watson-Crick geometries. We report here a unique case where AEGIS DNA has been used to execute a systematic evolution of ligands by exponential enrichment (SELEX) experiment. This AEGIS-SELEX was designed to create AEGIS oligonucleotides that bind to a line of breast cancer cells. AEGIS-SELEX delivered an AEGIS aptamer (ZAP-2012) built from six different kinds of nucleotides (the standard G, A, C, and T, and the AEGIS nonstandard P and Z nucleotides, the last having a nitro functionality not found in standard DNA). ZAP-2012 has a dissociation constant of 30 nM against these cells. The affinity is diminished or lost when Z or P (or both) is replaced by standard nucleotides and compares well with affinities of standard GACT aptamers selected against cell lines using standard SELEX. The success of AEGIS-SELEX relies on various innovations, including (i) the ability to synthesize GACTZP libraries, (ii) polymerases that PCR amplify GACTZP DNA with little loss of the AEGIS nonstandard nucleotides, and (iii) technologies to deep sequence GACTZP DNA survivors. These results take the next step toward expanding the power and utility of SELEX and offer an AEGIS-SELEX that could possibly generate receptors, ligands, and catalysts having sequence diversities nearer to that displayed by proteins.
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20
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Yang Z, Durante M, Glushakova LG, Sharma N, Leal NA, Bradley KM, Chen F, Benner SA. Conversion strategy using an expanded genetic alphabet to assay nucleic acids. Anal Chem 2013; 85:4705-12. [PMID: 23541235 DOI: 10.1021/ac400422r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methods to detect DNA and RNA (collectively xNA) are easily plagued by noise, false positives, and false negatives, especially with increasing levels of multiplexing in complex assay mixtures. Here, we describe assay architectures that mitigate these problems by converting standard xNA analyte sequences into sequences that incorporate nonstandard nucleotides (Z and P). Z and P are extra DNA building blocks that form tight nonstandard base pairs without cross-binding to natural oligonucleotides containing G, A, C, and T (GACT). The resulting improvements are assessed in an assay that inverts the standard Luminex xTAG architecture, placing a biotin on a primer (rather than on a triphosphate). This primer is extended on the target to create a standard GACT extension product that is captured by a CTGA oligonucleotide attached to a Luminex bead. By using conversion, a polymerase incorporates dZTP opposite template dG in the absence of dCTP. This creates a Z-containing extension product that is captured by a bead-bound oligonucleotide containing P, which binds selectively to Z. The assay with conversion produces higher signals than the assay without conversion, possibly because the Z/P pair is stronger than the C/G pair. These architectures improve the ability of the Luminex instruments to detect xNA analytes, producing higher signals without the possibility of competition from any natural oligonucleotides, even in complex biological samples.
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Affiliation(s)
- Zunyi Yang
- Foundation for Applied Molecular Evolution (FfAME), Gainesville, Florida 32601, United States.
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21
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Pinheiro VB, Loakes D, Holliger P. Synthetic polymers and their potential as genetic materials. Bioessays 2012; 35:113-22. [PMID: 23281109 DOI: 10.1002/bies.201200135] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
DNA and RNA are the only known natural genetic materials. Systematic modification of each of their chemical building blocks (nucleobase, sugar, and phosphate) has enabled the study of the key properties that make those nucleic acids genetic materials. All three moieties contribute to replication and, significantly, all three moieties can be replaced by synthetic analogs without loss of function. Synthetic nucleic acid polymers capable of storing and propagating information not only expand the central dogma, but also highlight that DNA and RNA are not unique chemical solutions for genetic information storage. By considering replication as a question of information transfer, we propose that any polymer that can be replicated could serve as a genetic material.
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Affiliation(s)
- Vitor B Pinheiro
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK.
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22
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Bag SS, Talukdar S, Matsumoto K, Kundu R. Triazolyl donor/acceptor chromophore decorated unnatural nucleosides and oligonucleotides with duplex stability comparable to that of a natural adenine/thymine pair. J Org Chem 2012; 78:278-91. [PMID: 23171090 DOI: 10.1021/jo302033f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We report the design and synthesis of triazolyl donor/acceptor unnatural nucleosides via click chemistry and studies on the duplex stabilization of DNA containing two such new nucleosides. The observed duplex stabilization among the self-pair/heteropair has been found to be comparable to that of a natural A/T pair. Our observations on the comparable duplex stabilization has been explained on the basis of possible π-π stacking and/or charge transfer interactions between the pairing partners. The evidence of ground-state charge transfer complexation came from the UV-vis spectra and the static quenching of fluorescence in a heteropair. We have also exploited one of our unnatural DNAs in stabilizing abasic DNA.
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Affiliation(s)
- Subhendu Sekhar Bag
- Bio-organic Chemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Guwahati-781039, India.
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Michelotti N, Johnson-Buck A, Manzo AJ, Walter NG. Beyond DNA origami: the unfolding prospects of nucleic acid nanotechnology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2012; 4:139-52. [PMID: 22131292 PMCID: PMC3360889 DOI: 10.1002/wnan.170] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nucleic acid nanotechnology exploits the programmable molecular recognition properties of natural and synthetic nucleic acids to assemble structures with nanometer-scale precision. In 2006, DNA origami transformed the field by providing a versatile platform for self-assembly of arbitrary shapes from one long DNA strand held in place by hundreds of short, site-specific (spatially addressable) DNA 'staples'. This revolutionary approach has led to the creation of a multitude of two-dimensional and three-dimensional scaffolds that form the basis for functional nanodevices. Not limited to nucleic acids, these nanodevices can incorporate other structural and functional materials, such as proteins and nanoparticles, making them broadly useful for current and future applications in emerging fields such as nanomedicine, nanoelectronics, and alternative energy.
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Yang Z, Chen F, Alvarado JB, Benner SA. Amplification, mutation, and sequencing of a six-letter synthetic genetic system. J Am Chem Soc 2011; 133:15105-12. [PMID: 21842904 DOI: 10.1021/ja204910n] [Citation(s) in RCA: 179] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The next goals in the development of a synthetic biology that uses artificial genetic systems will require chemistry-biology combinations that allow the amplification of DNA containing any number of sequential and nonsequential nonstandard nucleotides. This amplification must ensure that the nonstandard nucleotides are not unidirectionally lost during PCR amplification (unidirectional loss would cause the artificial system to revert to an all-natural genetic system). Further, technology is needed to sequence artificial genetic DNA molecules. The work reported here meets all three of these goals for a six-letter artificially expanded genetic information system (AEGIS) that comprises four standard nucleotides (G, A, C, and T) and two additional nonstandard nucleotides (Z and P). We report polymerases and PCR conditions that amplify a wide range of GACTZP DNA sequences having multiple consecutive unnatural synthetic genetic components with low (0.2% per theoretical cycle) levels of mutation. We demonstrate that residual mutation processes both introduce and remove unnatural nucleotides, allowing the artificial genetic system to evolve as such, rather than revert to a wholly natural system. We then show that mechanisms for these residual mutation processes can be exploited in a strategy to sequence "six-letter" GACTZP DNA. These are all not yet reported for any other synthetic genetic system.
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Affiliation(s)
- Zunyi Yang
- Foundation for Applied Molecular Evolution (FfAME), Gainesville, Florida 32601, United States
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