Influence of conformationally restricted pyrimidines on the activity of 10-23 DNAzymes.

ROBALDO, LAURA; IZZO, FRANCO; DELLAFIORE, MARÍA; PROIETTI, CECILIA J.; ELIZALDE, PATRICIA V.; MONTSERRAT, JAVIER M.; IRIBARREN, ADOLFO M.

BIOORGANIC & MEDICINAL CHEMISTRY.

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2012 vol. 20 p. 2581 - 2586

0968-0896

The catalytic core of a 10-23 DNAzyme was modified introducing conformationally restricted nucleosides such as (2’R)-, (2’S)-2’-deoxy-2’-C-methyluridine, (2’R)-, (2’S)-2’-deoxy-2’-C-methylcytidine, 2,2’-anhydrouridine and LNA-C, in one, two or three positions. Catalytic activities under pseudo first order conditions were compared at different Mg2+ concentrations using a short RNA substrate. At low Mg2+ concentrations, triple modified DNAzymes with similar kinetic performance to that displayed by the non-modified control were identified. In the search for a partial explanation of the obtained results, in-silico studies were carried out in order to explore the conformational behaviour of 2’-deoxy-2’-C-methylpyrimidines in the context of a loop structure, suggesting that at least partial flexibility is needed for the maintenance of activity. Finally, the modified 2’-C-methyl DNAzyme activity was tested assessing the inhibition of Stat3 expression and the decrease in cell proliferation using the human breast cancer cell line T47D.