Uniformly modified 2'-deoxy-2'-fluoro-phosphorothioate oligonucleotides as nuclease-resistant antisense compounds with high affinity and specificity for RNA targets
作者:Andrew M. Kawasaki、Martin D. Casper、Susan M. Freier、Elena A. Lesnik、Maryann C. Zounes、Lendell L. Cummins、Carolyn Gonzalez、P. Dan Cook
DOI:10.1021/jm00059a007
日期:1993.4
''Uniformly'' modified phosphodiester or phosphorothioate oligonucleotides incorporating 2'-deoxy-2'-fluoroadenosine, -guanosine, -uridine, and -cytidine, reported herein for the first time, when hybridized with RNA afforded consistent additive enhancement of duplex stability without compromising base-pair specificity. CD spectra of the 2'-deoxy-2'-fluoro-modified oligonucleotides hybridized with RNA indicated that the duplex adopts a fully A-form conformation. The 2'-deoxy-2'-fluoro-modified oligonucleotides in phosphodiester form were not resistant to nucleases; however, the modified phosphorothioate oligonucleotides were highly nuclease resistant and retained exceptional binding affinity to the RNA targets. The stabilizing effects of the 2'-deoxy-2'-fluoro modifications on RNA-DNA duplexes were shown to be superior to those of the 2'-O-methylribo substitutions. RNA hybrid duplexes with uniformly 2'-deoxy-2'-fluoro-modified oligonucleotides did not support HeLa RNase H activity; however, incorporation of the modifications into ''chimeric'' oligonucleotides has been shown to activate mammalian RNase H. ''Uniformly'' modified 2'-deoxy-2'-fluoro phosphorothioate oligonucleotides afforded antisense molecules with (1) high binding affinity and selectivity for the RNA target and (2) stability toward nucleases.
均一化修饰的磷酸二酯或硫代磷酸酯寡核苷酸,包含2'-脱氧-2'-氟腺苷、-鸟苷、-尿苷和-胞苷,首次在此报道,当它们与RNA杂交时,表现出一致的叠加性稳定性提升,同时不会影响碱基配对的特异性。2'-脱氧-2'-氟修饰的寡核苷酸与RNA杂交的圆二色光谱表明,杂交双链呈现完全的A型构象。以磷酸二酯形式存在的2'-脱氧-2'-氟修饰的寡核苷酸对核酸酶不具抵抗力;然而,以硫代磷酸酯形式存在的修饰寡核苷酸则具有极高的核酸酶抗性,并且保留了对RNA靶标的卓越结合亲和力。2'-脱氧-2'-氟修饰对RNA-DNA双链的稳定化效果被证明优于2'-O-甲基核糖的替代。与均一化2'-脱氧-2'-氟修饰寡核苷酸形成的RNA杂交双链不支持HeLa细胞中RNase H活性;然而,将修饰引入到“嵌合”寡核苷酸中已被证明可以激活哺乳动物的RNase H。均一化修饰的2'-脱氧-2'-氟硫代磷酸酯寡核苷酸提供了反义分子,具有(1)对RNA靶标的高结合亲和力和选择性,以及(2)对核酸酶的稳定性。