Azhayeva E, Azhayev A, Guzaev A, Lönnberg H
Department of Chemistry, University of Turku, Finland.
Nucleic Acids Res. 1995 Nov 11;23(21):4255-61. doi: 10.1093/nar/23.21.4255.
Complexing of looped and circular oligonucleotides, composed of either 2'-deoxyribo- or 2'-O-methylribonucleoside units, with completely matching or partially mismatching complementary DNA sequences was studied. Melting experiments revealed considerable differences among the stabilities of these hybrid complexes. Maximum stability and selectivity was displayed by oligomers 2 and 5. It was concluded that a linear stretch, attached to 1'-O- of 3'-deoxypsicothymidine unit (Z) increases the selectivity of hybridisation and stability of the complex as a whole. This allows one to aim the target DNA very precisely at its polyadenine part as well as at adjacent sequence simultaneously. Experiments on termination of primer extension catalysed by different DNA-polymerases--Sequenase, Klenow fragment and Tth--have demonstrated that looped oligomer 5, composed of 2'-O-methylribonucleosides appears to be a highly selective and potent inhibitor of replication in vitro. Features of looped oligonucleotides, composed of 2'-O-methylribonucleosides seem to be useful for design of highly specific antigene oligonucleotides.
研究了由2'-脱氧核糖核苷或2'-O-甲基核糖核苷单元组成的环状和环形寡核苷酸与完全匹配或部分错配的互补DNA序列的复合情况。熔解实验揭示了这些杂交复合物稳定性之间的显著差异。寡聚物2和5表现出最大的稳定性和选择性。得出的结论是，连接到3'-脱氧胸苷单元（Z）的1'-O-上的线性片段提高了杂交的选择性和整个复合物的稳定性。这使得能够非常精确地将靶DNA同时靶向其聚腺苷部分以及相邻序列。关于由不同DNA聚合酶——测序酶、Klenow片段和Tth——催化的引物延伸终止的实验表明，由2'-O-甲基核糖核苷组成的环状寡聚物5似乎是体外复制的一种高度选择性和有效的抑制剂。由2'-O-甲基核糖核苷组成的环状寡核苷酸的特性似乎有助于设计高度特异性的反基因寡核苷酸。
