Activity and Stability of Hammerhead Ribozymes containing 2’-C-Methyluridine: a new RNA Mimic

MARIANA GALLO, ROSEL KRETSCHMER-KAZEMI FAR, GEORG SCZAKIEL AND ADOLFO M. IRIBARREN

Chemistry and Biodiversity

Wiley Interscience VCH

Lugar: Suiza; Año: 2005 vol. 2 p. 198 - 204

1612-1872

We propose 2’-C-methylnucleotides as a new class of 2’-modified RNA mimics. These analogues are expected to provide 2’-hydroxyl groups capable of reproducing the interactions observed in natural RNA and to possess increased stability towards nucleases due to the presence of the methyl group. In this work, we investigate the catalytic activity and nuclease resistance of hammerhead ribozymes carrying 2’-C-methyluridines in positions 4 and 7 of the catalytic core. We describe the in vitro activity of these chimeric molecules and their stability in cell lysate, calf fetal serum and cell culture medium.  The data show that when only position 4 is modified, activity decreases two-fold; while when both 4 and 7 positions are substituted, a seven-fold drop in activity is observed. Regarding biological stability, the main increase of the half-life time is observed when position 7 is modified. These results suggest that 2’-C-methylnucleotides may be useful in the design of chemically synthesised RNA mimics with biological activity.