Locked 2鈥?Deoxy-2鈥?4鈥?Difluororibo Modified Nucleic Acids: Thermal Stability, Structural Studies, and siRNA Activity
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- 作者：Sa煤l Mart铆nez-Montero ; Glen F. Deleavey ; Nerea Mart铆n-Pintado ; Johans F. Fakhoury ; Carlos Gonz谩lez ; Masad J. Damha
- 刊名：ACS Chemical Biology
- 出版年：2015
- 出版时间：September 18, 2015
- 年：2015
- 卷：10
- 期：9
- 页码：2016-2023
- 全文大小：384K
- ISSN：1554-8937
文摘
2鈥?Deoxy-2鈥?4鈥?difluorouridine (2鈥?4鈥?diF-rU) was readily incorporated into DNA and RNA oligonucleotides via standard solid phase synthesis protocols. NMR and thermal denaturation (Tm) data of duplexes was consistent with the 2鈥?4鈥?diF-rU nucleotides adopting a rigid North (RNA-like) sugar conformation, as previously observed for the nucleoside monomer. The impact of this modification on Tm is neutral when incorporated within RNA:RNA duplexes, mildly destabilizing when located in the RNA strand of a DNA:RNA duplex, and highly destabilizing when inserted in the DNA strand of DNA:RNA and DNA:DNA duplexes. Molecular dynamics calculations suggest that the destabilization effect in DNA:DNA and DNA:RNA duplexes is the result of structural distortions created by A/B junctions within the helical structures. Quantum mechanics calculations suggest that the 鈥渘eutral鈥?effect imparted to A-form duplexes is caused by alterations in charge distribution that compensate the stabilizing effect expected for a pure North-puckered furanose sugar. 2鈥?4鈥?diF-RNA modified siRNAs were able to trigger RNA interference with excellent efficiency. Of note, incorporation of a few 2鈥?4鈥?diF-rU residues in the middle of the guide (antisense) strand afforded siRNAs that were more potent than the corresponding siRNAs containing LNA and 2鈥?F-ANA modifications, and as active as the 2鈥?F-RNA modified siRNAs.