Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Department of Chemistry and International Institute for, Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Angew Chem Int Ed Engl. 2021 Jul 5;60(28):15260-15265. doi: 10.1002/anie.202103440. Epub 2021 Jun 1.
The ability of aptamers to recognize a variety of different molecules has fueled their emergence as recognition agents to probe complex media and cells. Many detection strategies require aptamer binding to its target to result in a dramatic change in structure, typically from an unfolded to a folded state. Here, we report a strategy based on forced intercalation (FIT) that increases the scope of aptamer recognition by transducing subtle changes in aptamer structures into fluorescent readouts. By screening a library of green-fluorescent FIT-aptamers whose design is guided by computational modeling, we could identify hits that sense steroids like dehydroepiandrosterone sulfate (DHEAS) down to 1.3 μM with no loss in binding affinity compared to the unmodified aptamer. This enabled us to study DHEAS in clinical serum samples with several advantages over gold standard methods, including rapid readout (<30 min), simple instrumentation (plate-reader), and low sample volumes (10 μL).
适体识别各种不同分子的能力促使它们成为探测复杂介质和细胞的识别试剂。许多检测策略需要适体与靶标结合，导致结构发生显著变化，通常从无规卷曲到折叠状态。在这里，我们报告了一种基于强制嵌入（FIT）的策略，该策略通过将适体结构的细微变化转化为荧光读数来增加适体识别的范围。通过筛选由计算建模指导设计的绿色荧光 FIT-适体文库，我们可以识别出能够检测到脱氢表雄酮硫酸酯（DHEAS）等类固醇的适体，其检测下限低至 1.3μM，与未修饰的适体相比，结合亲和力没有损失。这使我们能够使用比金标准方法具有多个优势的方法来研究临床血清样本中的 DHEAS，包括快速读数（<30min）、简单的仪器（板读数器）和小样本量（10μL）。
