Stabilization of Telomeric I-Motif Structures by (2′S)-2′-Deoxy-2′-C-Methylcytidine Residues

G-quadruplexes and i-motifs are tetraplex structures present in telomeres and the promoter regions of oncogenes. The possibility of producing nanodevices with pH-sensitive functions has triggered interest in modified oligonucleotides with improved structural properties. We synthesized C-rich oligonu...

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Bibliographic Details
Authors: Aviñó, Anna, Dellafiore, María A., Gargallo, Raimundo, Bustamante González, Carlos Alberto, Iribarren, A.M, Montserrat, Javier M., Eritja Casadellà, Ramón
Format: article
Status:Versión aceptada para publicación
Publication Date:2017
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/152495
Online Access:http://hdl.handle.net/10261/152495
Access Level:Open access
Keyword:Circular dichroism
deoxymethylcytidine
i-motifs
NMR spectroscopy
telomeres
Description
Summary:G-quadruplexes and i-motifs are tetraplex structures present in telomeres and the promoter regions of oncogenes. The possibility of producing nanodevices with pH-sensitive functions has triggered interest in modified oligonucleotides with improved structural properties. We synthesized C-rich oligonucleotides carrying conformationally restricted (2′S)-2′-deoxy-2′-C-methyl-cytidine units. The effect of this modified nucleoside on the stability of intramolecular i-motifs from the vertebrate telomere was investigated by UV, CD, and NMR spectroscopy. The replacement of selected positions of the C-core with C-modified residues induced the formation of stable intercalated tetraplexes at near-neutral pH. This study demonstrates the possibility of enhancing the stability of the i-motif by chemical modification. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim