化学
核苷酸
位阻效应
寡核苷酸
核苷
核糖核酸
寡核苷酸合成
小干扰RNA
立体化学
核酸
复式(建筑)
基因沉默
生物化学
DNA
基因
作者
Dale C. Guenther,Shohei Mori,Shigeo Matsuda,Jason A. Gilbert,Jennifer L. S. Willoughby,Sarah Hyde,Anna Bisbe,Yongfeng Jiang,Saket Agarwal,Mimouna Madaoui,Maja M. Janas,Klaus Charissé,Martin A. Maier,Martin Egli,Muthiah Manoharan
摘要
Although 2′-deoxy-2′-α-F-2′-β-C-methyl (2′-F/Me) uridine nucleoside derivatives are a successful class of antiviral drugs, this modification had not been studied in oligonucleotides. Herein, we demonstrate the facile synthesis of 2′-F/Me-modified pyrimidine phosphoramidites and their subsequent incorporation into oligonucleotides. Despite the C3′-endo preorganization of the parent nucleoside, a single incorporation into RNA or DNA resulted in significant thermal destabilization of a duplex due to unfavorable enthalpy, likely resulting from steric effects. When located at the terminus of an oligonucleotide, the 2′-F/Me modification imparted more resistance to degradation than the corresponding 2′-fluoro nucleotides. Small interfering RNAs (siRNAs) modified at certain positions with 2′-F/Me had similar or better silencing activity than the parent siRNAs when delivered via a lipid nanoparticle formulation or as a triantennary N-acetylgalactosamine conjugate in cells and in mice. Modification in the seed region of the antisense strand at position 6 or 7 resulted in an activity equivalent to the parent in mice. Additionally, placement of the antisense strand at position 7 mitigated seed-based off-target effects in cell-based assays. When the 2′-F/Me modification was combined with 5′-vinyl phosphonate, both E and Z isomers had silencing activity comparable to the parent. In combination with other 2′-modifications such as 2′-O-methyl, the Z isomer is detrimental to silencing activity. Presumably, the equivalence of 5′-vinyl phosphonate isomers in the context of 2′-F/Me is driven by the steric and conformational features of the C-methyl-containing sugar ring. These data indicate that 2′-F/Me nucleotides are promising tools for nucleic acid-based therapeutic applications to increase potency, duration, and safety.
科研通智能强力驱动
Strongly Powered by AbleSci AI