Stabilization of telomeric i-motif structures by (2?S)-2?-deoxy-2?-C-methyl-cytidine residues

ANNA AVIÑÓ; MARÍA DELLAFIORE; RAIMUNDO GARGALLO; CARLOS GONZÁLEZ; ADOLFO IRIBARREN; JAVIER MONTSERRAT; RAMÓN ERITJA

CHEMBIOCHEM

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2017 vol. 18 p. 1 - 7

1439-4227

G-quadruplex and i-motif are tetraplex structurespresent in telomeres and promoter regions of oncogenes. The possibility ofproducing nanodevices with pH-sensitive functions has triggered the interestfor modified oligonucleotides with improved structural properties. Wesynthesized C-rich oligonucleotides carrying conformationally restricted (2?S)-2?-deoxy-2?-C-methyl-cytidine units. The effect of this modified nucleoside onthe stability of intramolecular i-motifs related to vertebrate telomere wasinvestigated by means of spectroscopic methods (UV, CD and NMR). Thereplacement of selected positions of the C-core by the appropriate C-modified residuesinduces astabilization of the i-motif structure obtaining stable intercalatedtetraplexesat pHs near neutrality. The study demonstrates the possibility ofenhancing the stability of i-motif by chemical modifications.