RAID3-An interleukin-6 receptor-binding aptamer with post-selective modification-resistant affinity
RAID3-An interleukin-6 receptor-binding aptamer with post-selective modification-resistant affinity
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DOI：
10.1080/15476286.2015.1079681
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发表时间：
2015-09-02
期刊：
影响因子：
4.1
通讯作者：
Hahn, Ulrich
中科院分区：
文献类型：
--
作者：
Mittelberger, Florian;Meyer, Cindy;Hahn, Ulrich
适体是一类新兴的高度特异性靶向配体。它们可以在体外被选择用于各种各样的靶点，从小分子到全细胞。大多数选择的适体是基于核酸的，允许化学合成和容易修饰。尽管它们的性质使它们成为用于广泛应用的有趣的候选药物和抗体或融合蛋白的有趣的替代品，但它们尚未被广泛使用。适体的一个主要缺点是它们对大量血清核酸酶的敏感性，导致它们在生物流体中快速降解。使用修饰的核酸已经成为克服这些缺点的常用策略，大大增加了它们在细胞培养条件下甚至在体内的半衰期。尽管用于适体选择的初始文库的预选择性修饰相对容易获得，但是已经选择的适体的选择性后修饰通常仍然是非常劳动密集的，并且经常损害适体结合其靶分子的能力。白细胞介素-6受体（IL-6 R）的新靶位点（结构域3）。我们进行了结构分析，并研究了适体的膜结合和可溶性形式（sIL-6 R）的IL-6 R的亲和力。此外，我们使用小角X射线散射对溶液中的适体进行了结构分析，并确定了其整体形状和寡聚状态。所有嘧啶与其2-氟类似物的后选择性交换显著增加了适体的稳定性，而不损害其对靶蛋白的亲和力。得到的修饰的适体可以缩短到其最小结合基序而不损失亲和力。
Aptamers are an emerging class of highly specific targeting ligands. They can be selected in vitro for a large variety of targets, ranging from small molecules to whole cells. Most aptamers selected are nucleic acid-based, allowing chemical synthesis and easy modification. Although their properties make them interesting drug candidates for a broad spectrum of applications and an interesting alternative to antibodies or fusion proteins, they are not yet broadly used. One major drawback of aptamers is their susceptibility to abundant serum nucleases, resulting in their fast degradation in biological fluids. Using modified nucleic acids has become a common strategy to overcome these disadvantages, greatly increasing their half-life under cell culture conditions or even in vivo. Whereas pre-selective modifications of the initial library for aptamer selection are relatively easy to obtain, post-selective modifications of already selected aptamers are still generally very labor-intensive and often compromise the aptamers ability to bind its target molecule.Here we report the selection, characterization and post-selective modification of a 34 nucleotide (nt) RNA aptamer for a non-dominant, novel target site (domain 3) of the interleukin-6 receptor (IL-6R). We performed structural analyses and investigated the affinity of the aptamer to the membrane-bound and soluble forms (sIL-6R) of the IL-6R. Further, we performed structural analyses of the aptamer in solution using small-angle X-ray scattering and determined its overall shape and oligomeric state. Post-selective exchange of all pyrimidines against their 2-fluoro analogs increased the aptamers stability significantly without compromising its affinity for the target protein. The resulting modified aptamer could be shortened to its minimal binding motif without loss of affinity.