• Open Access

Synthesis and Structural Characterization of Stable Branched DNA G-Quadruplexes Using the Trebler Phosphoramidite

Authors

  • Rubén Ferreira,

    1. Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona (Spain)
    2. Department of Chemistry and Molecular Pharmacology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri i Reixac 10, 08028 Barcelona (Spain)
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  • Dr. Margarita Alvira,

    1. Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona (Spain)
    2. Department of Chemistry and Molecular Pharmacology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri i Reixac 10, 08028 Barcelona (Spain)
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  • Dr. Anna Aviñó,

    1. Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona (Spain)
    2. Department of Chemistry and Molecular Pharmacology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri i Reixac 10, 08028 Barcelona (Spain)
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  • Dr. Irene Gómez-Pinto,

    1. Departmento de Química Física Biológica, Instituto de Química Física ‘Rocasolano', CSIC, Serrano 119, 28006 Madrid (Spain)
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  • Dr. Carlos González,

    1. Departmento de Química Física Biológica, Instituto de Química Física ‘Rocasolano', CSIC, Serrano 119, 28006 Madrid (Spain)
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  • Dr. Valérie Gabelica,

    1. Department of Chemistry, University of Liège, Allée de la Chimie Building B6c, 4000 Liège (Belgium)
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  • Dr. Ramon Eritja

    Corresponding author
    1. Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona (Spain)
    2. Department of Chemistry and Molecular Pharmacology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri i Reixac 10, 08028 Barcelona (Spain)
    • Department of Chemical and Biomolecular Nanotechnology, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Networking Centre on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona (Spain)
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Abstract

Guanine (G)-rich sequences can form a noncanonical four-stranded structure known as the G-quadruplex. G-quadruplex structures are interesting because of their potential biological properties and use in nanosciences. Here, we describe a method to prepare highly stable G-quadruplexes by linking four G-rich DNA strands to form a monomolecular G-quadruplex. In this method, one strand is synthesized first, and then a trebler molecule is added to simultaneously assemble the remaining three strands. This approach allows the introduction of specific modifications in only one of the strands. As a proof of concept, we prepared a quadruplex where one of the chains includes a change in polarity. A hybrid quadruplex is observed in ammonium acetate solutions, whereas in the presence of sodium or potassium, a parallel G-quadruplex structure is formed. In addition to the expected monomolecular quadruplexes, we observed the presence of dimeric G-quadruplex structures. We also applied the method to prepare G-quadruplexes containing a single 8-aminoguanine substitution and found that this single base stabilizes the G-quadruplex structure when located at an internal position.

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