High affinity nucleic acid aptamers for streptavidin incorporated into bi-specific capture ligands
High affinity nucleic acid aptamers for streptavidin incorporated into bi-specific capture ligands
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DOI：
10.1093/nar/30.10.e45
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发表时间：
2002-05-15
影响因子：
14.9
通讯作者：
James, W
中科院分区：
文献类型：
--
作者：
Tahiri-Alaoui, A;Frigotto, L;James, W
我们已经分离出2 '-氟取代的RNA适体，其以约7 +/-1.8 nM的亲和力结合链霉亲和素（SA），与最近描述的肽适体相当。与SA的结合不被预先用生物素饱和所阻止，使得核酸适体能够形成有用的三元复合物。突变、二级结构分析、核糖核酸酶足迹和缺失分析为SA结合适体的基本结构特征提供了证据。为了提供开发这些适体的通用方法，我们生产了衍生物，其中它们与天然结构的RNA元件CopT或CopA融合。同时，我们产生了与互补CopA或CopT元件融合的CD 4结合适体的衍生物。当混合时，这两种嵌合适体凭借CopA-CopT互补性迅速杂交，形成稳定的双功能适体，我们称之为“适体”。我们表明，CD 4-SA结合适体可用于捕获到SA衍生的表面上的CD 4，说明它们作为间接亲和配体的一般效用。
We have isolated 2'-Fluoro-substituted RNA aptamers that bind to streptavidin (SA) with an affinity around 7 +/- 1.8 nM, comparable with that of recently described peptide aptamers. Binding to SA was not prevented by prior saturation with biotin, enabling nucleic acid aptamers to form useful ternary complexes. Mutagenesis, secondary structure analysis, ribonuclease footprinting and deletion analysis provided evidence for the essential structural features of SA-binding aptamers. In order to provide a general method for the exploitation of these aptamers, we produced derivatives in which they were fused to the naturally structured RNA elements, CopT or CopA. In parallel, we produced derivatives of CD4-binding aptamers fused to the complementary CopA or CopT elements. When mixed, these two chimeric aptamers rapidly hybridized, by virtue of CopA-CopT complementarity, to form stable, bi-functional aptamers that we called 'adaptamers'. We show that a CD4-SA-binding adaptamer can be used to capture CD4 onto a SA-derivatized surface, illustrating their general utility as indirect affinity ligands.