Single strand targeted triplex formation: Physicochemical and biochemical properties of foldback triplexes
Single strand targeted triplex formation: Physicochemical and biochemical properties of foldback triplexes
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DOI：
10.1080/07391102.1996.10508931
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发表时间：
1996-08-01
影响因子：
4.4
通讯作者：
Agrawal, S
中科院分区：
文献类型：
--
作者：
Kandimalla, ER;Manning, A;Agrawal, S
研究了同时含有Watson-Crick和Hoogsteen氢键结构域并通过核苷酸环(FTFOS)连接的寡核苷酸与DNA和RNA单链靶标的结合亲和酸特异性。热变性研究表明，FTFO与其靶标的结合亲和力高于反义(双链形成)和反基因(三链形成)寡核苷酸，因为Watson-Crick和Hoogsteen结构域都参与了相互作用。对含有不同大小和环序列的FTFO的研究表明，4-6个碱基长的环最适合结合；环序列对结合没有显著影响。FTFO比反义和抗基因寡核苷酸具有更大的序列特异性，因为它们读取目标序列两次。S1-、P1-和绿豆核酸酶保护实验表明，DNA FTFO与DNA靶链形成稳定的三倍体，而与RNA靶链形成弱三倍体或无三倍体。凝胶迁移率改变分析用于确定FTFO与DNA和RNA靶标的结合。与DNA靶链形成的折叠三倍体的圆二色谱(CD)与B-DNA光谱相似，表明该三倍体具有B型构象。
Oligodeoxyribonucleotides containing both Watson-Crick and Hoogsteen hydrogen bonding domains joined by a nucleotide loop (FTFOs) are studied for their binding affinity acid specificity to the DNA and RNA single-stranded targets. Thermal denaturation studies reveal that FTFOs have high binding affinity for their targets than do antisense (duplex forming) and antigene (triplex forming) oligonucleotides, because of involvement of both the Watson-Crick and Hoogsteen domains in the interaction. Studies with FTFOs containing different sizes and sequences of loops show that 4-6 bases long loops are optimum for binding; loop sequence does not have a dramatic effect on binding. The FTFOs have greater sequence specificity than do antisense and antigene oligonucleotides because they read the target sequence twice. S1-, P1- and mung bean nuclease protection assays show that the DNA FTFO forms a stable tripler with the DNA target strand, but a weak or no tripler with the RNA target strand. Gel mobility shift assay is used to determine binding of FTFOs to DNA and RNA targets. The circular dichroism (CD) spectrum of the foldback tripler formed with the DNA target strand resembles the B-DNA spectrum, suggesting that the tripler has a B-type of conformation.