Influence of conformationally restricted pyrimidines on the activity of 10–23 DNAzymes
作者:Laura Robaldo、Franco Izzo、María Dellafiore、Cecilia Proietti、Patricia V. Elizalde、Javier M. Montserrat、Adolfo M. Iribarren
DOI:10.1016/j.bmc.2012.02.047
日期:2012.4
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 behavior of 2'-deoxy-2'-C-methyl-pyrimidines 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. (C) 2012 Elsevier Ltd. All rights reserved.