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Abstract
DNA has played an early and powerful role in the development of bottom-up nanotechnologies, not least because of DNA's precise, predictable, and controllable properties of assembly on the nanometer scale. Watson-Crick complementarity has been used to build complex 2D and 3D architectures and design a number of nanometer-scale systems for molecular computing, transport, motors, and biosensing applications. Most of such devices are built with classical B-DNA helices and involve classical A-T/U and G-C base pairs. However, in addition to the above components underlying the iconic double helix, a number of alternative pairing schemes of nucleobases are known. This review focuses on two of these noncanonical classes of DNA helices: G-quadruplexes and the i-motif. The unique properties of these two classes of DNA helix have been utilized toward some remarkable constructions and applications: G-wires; nanostructures such as DNA origami; reconfigurable structures and nanodevices; the formation and utilization of hemin-utilizing DNAzymes, capable of generating varied outputs from biosensing nanostructures; composite nanostructures made up of DNA as well as inorganic materials; and the construction of nanocarriers that show promise for the therapeutics of diseases.
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Affiliation(s)
- Jean-Louis Mergny
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering , Nanjing University , Nanjing 210023 , China.,ARNA Laboratory , Université de Bordeaux, Inserm U 1212, CNRS UMR5320, IECB , Pessac 33600 , France.,Institute of Biophysics of the CAS , v.v.i., Královopolská 135 , 612 65 Brno , Czech Republic
| | - Dipankar Sen
- Department of Molecular Biology & Biochemistry , Simon Fraser University , Burnaby , British Columbia V5A 1S6 , Canada.,Department of Chemistry , Simon Fraser University , Burnaby , British Columbia V5A 1S6 , Canada
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2
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Jin H, Kim MG, Ko SB, Kim DH, Lee BJ, Macgregor RB, Shim G, Oh YK. Stemmed DNA nanostructure for the selective delivery of therapeutics. NANOSCALE 2018; 10:7511-7518. [PMID: 29637946 DOI: 10.1039/c7nr08558c] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
DNA has emerged as a biocompatible biomaterial that may be considered for various applications. Here, we report tumor cell-specific aptamer-modified DNA nanostructures for the specific recognition and delivery of therapeutic chemicals to cancer cells. Protein tyrosine kinase (PTK)7-specific DNA aptamer sequences were linked to 15 consecutive guanines. The resulting aptamer-modified product, AptG15, self-assembled into a Y-shaped structure. The presence of a G-quadruplex at AptG15 was confirmed by circular dichroism and Raman spectroscopy. The utility of AptG15 as a nanocarrier of therapeutics was tested by loading the photosensitizer, methylene blue (MB), to the G-quadruplex as a model drug. The generated MB-loaded AptG15 (MB/AptG15) showed specific and enhanced uptake to CCRF-CEM cells, which overexpress PTK7, compared with Ramos cells, which lack PTK7, or CCRF-CEM cells treated with a PTK7-specific siRNA. The therapeutic activity of MB/AptG15 was tested by triggering its photodynamic effects. Upon 660 nm light irradiation, MB/AptG15 showed greater reactive oxygen species generation and anticancer activity in PTK7-overexpressing cells compared to cells treated with MB alone, those treated with AptG15, and other comparison groups. AptG15 stemmed DNA nanostructures have significant potential for the cell-type-specific delivery of therapeutics, and possibly for the molecular imaging of target cells.
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Affiliation(s)
- H Jin
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
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Varizhuk AM, Sekridova AV, Tankevich MV, Podgorsky VS, Smirnov IP, Pozmogova GE. Conformational polymorphysm of G-rich fragments of DNA Alu-repeats. II. The putative role of G-quadruplex structures in genomic rearrangements. BIOCHEMISTRY MOSCOW-SUPPLEMENT SERIES B-BIOMEDICAL CHEMISTRY 2017. [DOI: 10.1134/s1990750817020093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Varizhuk AM, Sekridova AV, Tankevich MV, Podgorsky VS, Smirnov IP, Pozmogova GE. [Conformational polymorphysm of G-rich fragments of DNA Alu-repeats. II. the putative role of G-quadruplex structures in genomic rearrangements]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2017; 62:630-637. [PMID: 28026805 DOI: 10.18097/pbmc20166206630] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Three evolutionary conserved sites of Alu repeats (PQS2, PQS3 and PQS4) were shown to form stable inter- and intramolecular G-quadruplexes (GQs) in vitro. Structures and topologies of these GQs were elucidated using spectral methods. Self-association of G-rich Alu fragments was studied. Dimeric GQ formation from two distal identical or different putative quadruplex sites - (PQS2)2, (PQS3)2 or PQS2-PQS3 - within one lengthy DNA strand was demonstrated by a FRET-based method. Oligomer PQS4 (folded into a parallel intramolecular GQ) was shown to form stacks of quadruplexes that are stabilized by stacking interactions of external G-tetrads (this was confirmed by DOSY NMR, AFM microscopy and differential CD spectroscopy). Comparative analysis of the properties of various GQs allowed us to put forward a hypothesis of two general mechanisms of intermolecular GQ-dependant genomic rearrangements: 1) formation of a dimeric GQs; 2) association of pre-folded intramolecular parallel GQs from different strands into GQ-stacks. Thus, the observed co-localization of G-rich motifs of Alu elements with double-strand break hotspots and rearrangement hotspots may be accounted for by the specific secondary structure of these motifs. At the same time, this is likely primarily due to high abundance of such G-rich Alu fragments in the genome.
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Affiliation(s)
- A M Varizhuk
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - A V Sekridova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - M V Tankevich
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - V S Podgorsky
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - I P Smirnov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - G E Pozmogova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
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Voges M, Schneider C, Sinn M, Hartig JS, Reimer R, Hauber J, Moelling K. Abolishing HIV-1 infectivity using a polypurine tract-specific G-quadruplex-forming oligonucleotide. BMC Infect Dis 2016; 16:358. [PMID: 27450669 PMCID: PMC4957839 DOI: 10.1186/s12879-016-1713-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/12/2016] [Indexed: 02/04/2023] Open
Abstract
Background HIV is primarily transmitted by sexual intercourse and predominantly infects people in Third World countries. Here an important medical need is self-protection for women, particularly in societies where condoms are not widely accepted. Therefore, availability of antiviral microbicides may significantly reduce sexual HIV transmission in such environments. Methods Here, we investigated structural characteristics and the antiviral activity of the polypurine tract (PPT)-specific ODN A, a 54-mer oligodeoxynucleotide (ODN) that has been previously shown to trigger the destruction of viral RNA genomes by prematurely activating the retroviral RNase H. The stability of ODN A and mutants thereof was tested at various storage conditions. Furthermore, antiviral effects of ODN A were analyzed in various tissue culture HIV-1 infection models. Finally, circular dichroism spectroscopy was employed to gain insight into the structure of ODN A. Results We show here that ODN A is a powerful tool to abolish HIV-1 particle infectivity, as required for a candidate compound in vaginal microbicide applications. We demonstrate that ODN A is not only capable to prematurely activate the retroviral RNase H, but also prevents HIV-1 from entering host cells. ODN A also exhibited extraordinary stability lasting several weeks. Notably, ODN A is biologically active under various storage conditions, as well as in the presence of carboxymethylcellulose CMC (K-Y Jelly), a potential carrier for application as a vaginal microbicide. ODN A’s remarkable thermostability is apparently due to its specific, guanosine-rich sequence. Interestingly, these residues can form G-quadruplexes and may lead to G-based DNA hyperstructures. Importantly, the pronounced antiviral activity of ODN A is maintained in the presence of human semen or semen-derived enhancer of virus infection (SEVI; i.e. amyloid fibrils), both known to enhance HIV infectivity and reduce the efficacy of some antiviral microbicides. Conclusions Since ODN A efficiently inactivates HIV-1 and also displays high stability and resistance against semen, it combines unique and promising features for its further development as a vaginal microbicide against HIV.
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Affiliation(s)
- Maike Voges
- Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
| | - Carola Schneider
- Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
| | - Malte Sinn
- Department of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany
| | - Jörg S Hartig
- Department of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany
| | - Rudolph Reimer
- Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
| | - Joachim Hauber
- Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany. .,German Center for Infection Research (DZIF), partner site, Hamburg, Germany.
| | - Karin Moelling
- Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany.,Institute of Medical Virology, University of Zurich, Gloriastrasse 32, 8006, Zurich, Switzerland.,Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
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Yurenko YP, Novotný J, Mitoraj MP, Sklenář V, Michalak A, Marek R. Nucleic Acid Quadruplexes Based on 8-Halo-9-deazaxanthines: Energetics and Noncovalent Interactions in Quadruplex Stems. J Chem Theory Comput 2014; 10:5353-65. [DOI: 10.1021/ct5007554] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yevgen P. Yurenko
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ − 62500 Brno, Czech Republic
| | - Jan Novotný
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ − 62500 Brno, Czech Republic
- National
Center for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Mariusz P. Mitoraj
- Department
of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, Krakow PL-30060, Poland
| | - Vladimir Sklenář
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ − 62500 Brno, Czech Republic
- National
Center for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- Department
of Chemistry, Faculty of Science, Masaryk University, Kamenice
5, 625 00 Brno, Czech Republic
| | - Artur Michalak
- Department
of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, Krakow PL-30060, Poland
| | - Radek Marek
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 5/A4, CZ − 62500 Brno, Czech Republic
- National
Center for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- Department
of Chemistry, Faculty of Science, Masaryk University, Kamenice
5, 625 00 Brno, Czech Republic
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7
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Zhou J, Rosu F, Amrane S, Korkut DN, Gabelica V, Mergny JL. Assembly of chemically modified G-rich sequences into tetramolecular DNA G-quadruplexes and higher order structures. Methods 2014; 67:159-68. [DOI: 10.1016/j.ymeth.2014.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/20/2013] [Accepted: 01/02/2014] [Indexed: 10/25/2022] Open
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Tlučková K, Marušič M, Tóthová P, Bauer L, Šket P, Plavec J, Viglasky V. Human Papillomavirus G-Quadruplexes. Biochemistry 2013; 52:7207-16. [DOI: 10.1021/bi400897g] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katarína Tlučková
- Department
of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Safarik University, 04001 Kosice, Slovakia
| | - Maja Marušič
- Slovenian
NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Petra Tóthová
- Department
of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Safarik University, 04001 Kosice, Slovakia
| | - Lubos Bauer
- Department
of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Safarik University, 04001 Kosice, Slovakia
| | - Primož Šket
- Slovenian
NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
- EN-FIST Center of Excellence, SI-1000 Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian
NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
- EN-FIST Center of Excellence, SI-1000 Ljubljana, Slovenia
- Faculty
of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Viktor Viglasky
- Department
of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Safarik University, 04001 Kosice, Slovakia
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Palacký J, Vorlíčková M, Kejnovská I, Mojzeš P. Polymorphism of human telomeric quadruplex structure controlled by DNA concentration: a Raman study. Nucleic Acids Res 2013; 41:1005-16. [PMID: 23193257 PMCID: PMC3553954 DOI: 10.1093/nar/gks1135] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 10/22/2012] [Indexed: 01/16/2023] Open
Abstract
DNA concentration has been recently suggested to be the reason why different arrangements are revealed for K(+)-stabilized human telomere quadruplexes by experimental methods requiring DNA concentrations differing by orders of magnitude. As Raman spectroscopy can be applied to DNA samples ranging from those accessible by absorption and CD spectroscopies up to extremely concentrated solutions, gels and even crystals; it has been used here to clarify polymorphism of a core human telomeric sequence G(3)(TTAG(3))(3) in the presence of K(+) and Na(+) ions throughout wide range of DNA concentrations. We demonstrate that the K(+)-structure of G(3)(TTAG(3))(3) at low DNA concentration is close to the antiparallel fold of Na(+)-stabilized quadruplex. On the increase of G(3)(TTAG(3))(3) concentration, a gradual transition from antiparallel to intramolecular parallel arrangement was observed, but only for thermodynamically equilibrated K(+)-stabilized samples. The transition is synergically supported by increased K(+) concentration. However, even for extremely high G(3)(TTAG(3))(3) and K(+) concentrations, an intramolecular antiparallel quadruplex is spontaneously formed from desalted non-quadruplex single-strand after addition of K(+) ions. Thermal destabilization or long dwell time are necessary to induce interquadruplex transition. On the contrary, Na(+)-stabilized G(3)(TTAG(3))(3) retains its antiparallel folding regardless of the extremely high DNA and/or Na(+) concentrations, thermal destabilization or annealing.
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Affiliation(s)
- Jan Palacký
- Charles University in Prague, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno and CEITEC—Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Michaela Vorlíčková
- Charles University in Prague, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno and CEITEC—Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Iva Kejnovská
- Charles University in Prague, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno and CEITEC—Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
| | - Peter Mojzeš
- Charles University in Prague, Faculty of Mathematics and Physics, Institute of Physics, Ke Karlovu 5, CZ-121 16 Prague 2, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno and CEITEC—Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic
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Abu-Ghazalah RM, Rutledge S, Lau LWY, Dubins DN, Macgregor RB, Helmy AS. Concentration-dependent structural transitions of human telomeric DNA sequences. Biochemistry 2012; 51:7357-66. [PMID: 22931349 DOI: 10.1021/bi300689t] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Oligodeoxyribonucleotides (ODNs) that have four repeats of the human telomeric sequence d(TTAGGG)(n) can assume multiple monomolecular G-quadruplex topologies. These are determined by the cation species present, the bases at the 5' or 3' end, and the sample preparation technique. In this work, we report our studies of the concentration dependence of the circular dichroism (CD) and the vibrational modes probed by Raman scattering of three previously characterized monomolecular G-quadruplexes: H-Tel, d[5'-A(GGGTTA)(3)GGG-3']; hybrid-1, d[5'-AAA(GGGTTA)(3)GGGAA-3']; and hybrid-2, d[5'-TTA(GGGTTA)(3)GGGTT-3']. At high (millimolar) ODN concentrations, we observed a transformation of the CD spectrum of H-Tel, with a relaxation time on the order of 10 h. Analysis of the kinetics of this process is consistent with the formation of an aggregated complex of folded H-Tel monomers. Upon dilution, the aggregates dissociate rapidly, yielding spectra identical to those of monomeric H-Tel. Both hybrid sequences undergo a similar transition under high-salt (1 M) conditions. The measurements suggest that for these ODN concentrations, which are typically used in high-resolution spectroscopies, the monomolecular G-quadruplex structures undergo a transition to multimolecular structures at room temperature. Guided by our findings, we propose that the terminal bases of the hybrid-1 and hybrid-2 ODNs impede the formation of these aggregates; however, in solutions containing 1 M salt, the hybrid oligonucleotides aggregate.
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Affiliation(s)
- Rashid M Abu-Ghazalah
- Edward S. Rogers Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
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Eftekhari F, Lee A, Kumacheva E, Helmy AS. Examining metal nanoparticle surface chemistry using hollow-core, photonic-crystal, fiber-assisted SERS. OPTICS LETTERS 2012; 37:680-2. [PMID: 22344146 DOI: 10.1364/ol.37.000680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In this Letter, we demonstrate the efficacy of hollow core photonic crystal fibers (HCPCFs) as a surface-enhanced Raman spectroscopy (SERS) platform for investigating the ligand exchange process on the surface of gold nanoparticles. Raman measurements carried out using this platform show the capability to monitor minute amounts of surface ligands on gold nanoparticles used as an SERS substrate. The SERS signal from an HCPCF exhibits a tenfold enhancement compared to that in a direct sampling scheme using a cuvette. Using exchange of cytotoxic cetyltrimethylammonium bromide with α-methoxy-ω-mercaptopoly(ethylene glycol) on the surface of gold nanorods as an exemplary system, we show the feasibility of using HCPCF SERS to monitor the change in surface chemistry of nanoparticles.
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Affiliation(s)
- Fatemeh Eftekhari
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.
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Virgilio A, Esposito V, Citarella G, Pepe A, Mayol L, Galeone A. The insertion of two 8-methyl-2'-deoxyguanosine residues in tetramolecular quadruplex structures: trying to orientate the strands. Nucleic Acids Res 2011; 40:461-75. [PMID: 21908403 PMCID: PMC3245916 DOI: 10.1093/nar/gkr670] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this article, we report a structural study, based on NMR and CD spectroscopies, and molecular modelling of all possible d(TG3T) and d(TG4T) analogues containing two 8-methyl-2′-deoxyguanosine residues (M). Particularly, the potential ability of these modified residues to orientate the strands and then to affect the folding topology of tetramolecular quadruplex structures has been investigated. Oligodeoxynucleotides (ODNs) TMMGT (T12) and TMMGGT (F12) form parallel tetramolecular quadruplexes, characterized by an all-syn M-tetrad at the 5′-side stacked to all-anti M- and G-tetrads. ODNs TMGMT (T13) and TMGGMT (F14) form parallel tetramolecular quadruplexes, in which an all-anti G core is sandwiched between two all-syn M-tetrads at the 5′- and the 3′-side. Notably, the quadruplex formed by T13 corresponds to an unprecedented structure in which the syn residues exceed in number the anti ones. Conversely, ODN TGMGMT (F24) adopts a parallel arrangement in which all-anti G-tetrads alternate with all-syn M-tetrads. Most importantly, all data strongly suggest that ODN TMGMGT (F13) forms an unprecedented anti-parallel tetramolecular quadruplex in which G and M residues adopt anti and syn glycosidic conformations, respectively. This article opens up new understandings and perspectives about the intricate relationship between the quadruplex strands orientation and the glycosidic conformation of the residues.
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Affiliation(s)
- Antonella Virgilio
- Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Via D. Montesano 49, I-80131 Napoli, Italy
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Mak JSW, Farah AA, Chen F, Helmy AS. Photonic crystal fiber for efficient Raman scattering of CdTe quantum dots in aqueous solution. ACS NANO 2011; 5:3823-3830. [PMID: 21517094 DOI: 10.1021/nn200157z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A novel hollow-core photonic crystal fiber platform was used for the first time to observe clear vibrational modes of the CdTe core, CdS(0.7)Te(0.3) interface, and carboxylate-metal complexes in dilute aqueous CdTe quantum dot (QD) solutions. These modes demonstrate the presence of crystalline cores, defects, and surface passivation responsible for photoluminescent efficiency and stability. In addition, 3-mercaptopropionic acid (MPA)-capped QDs show higher crystallinity and stability than those capped with thioglycolic acid (TGA) and 1-thioglycerol (TG). This detailed, nondestructive characterization was carried out using Raman spectroscopy for solutions with QD concentration of 2 mg/mL, which is similar to their concentration during synthesis process. This platform can be extended to the in situ studies of any colloidal nanoparticles and aqueous solutions of relevant biological samples using Raman spectroscopy.
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Affiliation(s)
- Jacky S W Mak
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4 Canada
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