Triple-helix formation by alpha oligodeoxynucleotides and alpha oligodeoxynucleotide-intercalator conjugates.
Triple-helix formation by alpha oligodeoxynucleotides and alpha oligodeoxynucleotide-intercalator conjugates.
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由α寡脱氧核苷酸和α寡脱氧核苷酸-嵌入剂缀合物形成三螺旋。
DOI：
10.1073/pnas.88.14.6023
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发表时间：
1991
影响因子：
11.1
通讯作者：
C. Hélène
中科院分区：
文献类型：
--
作者：
J. Sun;C. Giovannangeli;J. Francois;R. Kurfurst;T. Montenay‐Garestier;U. Asseline;T. Saison;N. Thuong;C. Hélène
双链DNA中的碱基对序列可以被同嘧啶寡核苷酸识别，同嘧啶寡核苷酸与同嘌呤的大沟结合，从而形成局部三螺旋。为了使寡脱氧核苷酸对核酸酶具有抗性，我们用合成的（α）端基异构体取代了核苷酸单元的天然（β）端基异构体。11-mer α寡脱氧核苷酸5 '-d（TCTCCTCCTTT）-3'以相对于高嘌呤链的反平行方向结合于DNA的大沟，而β寡核苷酸采用平行方向。当嵌入剂连接到α寡脱氧核苷酸的3'端时，观察到三螺旋的强稳定性。选择人免疫缺陷病毒前病毒DNA的16个碱基对的同嘌呤、同嘧啶序列作为16聚体同嘧啶α寡脱氧核苷酸的靶。一种限制酶，在高嘌呤连接处切割DNA。高嘧啶序列被三螺旋的形成所抑制。被嵌入剂取代的16-mer α寡脱氧核苷酸比未取代的寡聚体的效率高约20倍。核酸酶抗性α寡脱氧核苷酸提供了在DNA水平上控制基因表达的额外可能性。
Base-pair sequences in double-stranded DNA can be recognized by homopyrimidine oligonucleotides that bind to the major groove at homopurine.homopyrimidine sequences thereby forming a local triple helix. To make oligodeoxynucleotides resistant to nucleases, we replaced the natural (beta) anomers of the nucleotide units by the synthetic (alpha) anomers. The 11-mer alpha oligodeoxynucleotide 5'-d(TCTCCTCCTTT)-3' binds to the major groove of DNA in an antiparallel orientation with respect to the homopurine strand, whereas a beta oligonucleotide adopts a parallel orientation. When an intercalating agent was attached to the 3' end of the alpha oligodeoxynucleotide, a strong stabilization of the triple helix was observed. A 16-base-pair homopurine.homopyrimidine sequence of human immunodeficiency virus proviral DNA was chosen as a target for a 16-mer homopyrimidine alpha oligodeoxynucleotide. A restriction enzyme that cleaves DNA at the junction of the homopurine.homopyrimidine sequence was inhibited by triple-helix formation. The 16-mer alpha oligodeoxynucleotide substituted by an intercalating agent was approximately 20 times more efficient than the unsubstituted oligomer. Nuclease-resistant alpha oligodeoxynucleotides offer additional possibilities to control gene expression at the DNA level.