Understanding the binding of split aptamer/its target could become a breakthrough in the application of split aptamer. Herein, vascular endothelial growth factor (VEGF), a major biomarker of human diseases, was used as a model, and its interaction with split aptamer was explored with single molecule force spectroscopy (SMFS). SMFS demonstrated that the interaction force of split aptamer/VEGF165 was 169.44 ± 6.59 pN at the loading rate of 35.2 nN/s, and the binding probability of split aptamer/VEGF165 was dependent on the concentration of VEGF165 . On the basis of dynamic force spectroscopy results, one activation barrier in the dissociation process of split aptamer/VEGF165 complexes was revealed, which was similar to that of the intact aptamer/VEGF165 . Besides, the dissociation rate constant (koff ) of split aptamer/VEGF165 was close to that of intact aptamer/VEGF165 , and the interaction force of split aptamer/VEGF165 was higher than the force of intact aptamer/VEGF165 . It indicated that split aptamer also possessed high affinity with VEGF165 . The work can provide a new method for exploring the interaction of split aptamer/its targets at single-molecule level.

中文翻译：

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使用单分子力谱研究分裂适体和血管内皮生长因子 165 之间的相互作用。

了解分裂适体与其靶标的结合可能成为分裂适体应用的一个突破。在本文中，血管内皮生长因子（VEGF）是人类疾病的主要生物标志物，被用作模型，并通过单分子力谱（SMFS）探索其与分裂适体的相互作用。SMFS表明，在35.2 nN/s的加载速率下，分裂适体/VEGF165的相互作用力为169.44±6.59 pN，分裂适体/VEGF165的结合概率取决于VEGF165的浓度。基于动态力谱结果，揭示了分裂适体/VEGF165 复合物解离过程中的一个激活障碍，这与完整适体/VEGF165 的相似。除了，分裂适体/VEGF165的解离速率常数(koff)接近于完整适体/VEGF165，分裂适体/VEGF165的相互作用力高于完整适体/VEGF165。这表明分裂适体与VEGF165也具有高亲和力。该工作可以为在单分子水平上探索分裂适体与其靶标的相互作用提供一种新方法。