Sczepanski Jonathan T, Joyce Gerald F
Departments of Chemistry and Molecular Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
J Am Chem Soc. 2013 Sep 11;135(36):13290-3. doi: 10.1021/ja406634g. Epub 2013 Aug 28.
An L-RNA aptamer was developed that binds the natural D-form of the HIV-1 trans-activation responsive (TAR) RNA. The aptamer initially was obtained as a D-aptamer against L-TAR RNA through in vitro selection. Then the corresponding L-aptamer was prepared by chemical synthesis and used to bind the desired target. The L-aptamer binds D-TAR RNA with a Kd of 100 nM. It binds D-TAR exclusively at the six-nucleotide distal loop, but does so through tertiary interactions rather than simple Watson-Crick pairing. This complex is the first example of two nucleic acids molecules of opposing chirality that interact through a mode of binding other than primary structure. Binding of the L-aptamer to D-TAR RNA inhibits formation of the Tat-TAR ribonucleoprotein complex that is essential for TAR function. This suggests that L-aptamers, which are intrinsically resistant to degradation by ribonucleases, might be pursued as an alternative to antisense oligonucleotides to target structured RNAs of biological or therapeutic interest.
开发了一种L型RNA适体，它能结合HIV-1反式激活应答（TAR）RNA的天然D型。该适体最初是通过体外筛选获得的针对L-TAR RNA的D型适体。然后通过化学合成制备相应的L型适体，并用于结合所需靶标。该L型适体以100 nM的解离常数（Kd）结合D-TAR RNA。它仅在六核苷酸远端环处结合D-TAR，但通过三级相互作用而非简单的沃森-克里克配对。这种复合物是两个具有相反手性的核酸分子通过除一级结构之外的结合模式相互作用中的首个例子。L型适体与D-TAR RNA的结合抑制了Tat-TAR核糖核蛋白复合物的形成，而该复合物对TAR功能至关重要。这表明，由于L型适体对核糖核酸酶的降解具有内在抗性，可能会被用作反义寡核苷酸的替代物，以靶向具有生物学或治疗意义的结构化RNA。
