Conclusion
The selected 45-mer truncated RNA aptamer specifically and avidly bound DENV MTase and competitively inhibited its methylation activity, and thus could be useful for the development of anti-DENV agents.
Results
We identified 2'-fluoro-modified RNA aptamers that can specifically bind DENV serotype 2 (DENV2) MTase using systematic evolution of ligands by exponential enrichment technology. We truncated the chosen aptamer into a 45-mer RNA sequence that can bind DENV2 MTase with K d ~ 28 nM and inhibit N-7 methylation activity of the protein. Moreover, the 45-mer truncated aptamer could not only bind with an K d ~ 15.6 nM but also inhibit methylation activity of DENV serotype 3 (DENV3) MTase. The 45-mer aptamer competitively impeded binding of both DENV2 and DENV3 genomic RNA to MTase of each serotype.