Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, 100101 Beijing, China.
Langmuir. 2012 Jan 10;28(1):707-13. doi: 10.1021/la203954x. Epub 2011 Dec 2.
Aptamers are a new class of molecular probes for protein recognition, detection, and inhibition. Multivalent aptamer-protein binding through aptamer assembly has been currently developed as an effective way to achieve higher protein affinity and selectivity. In this study, the specific interaction between bivalent aptamer Bi-8S and thrombin has been measured directly and quantitatively by atomic force microscopy to investigate the unbinding dynamics and dissociation energy landscape of the multivalent interaction. Bivalent aptamer Bi-8S contains thrombin's two aptamers, 15apt and 27apt, which are linked by eight spacer phosphoramidites. The results revealed the sequential dissociation of the two aptamers. Moreover, the dynamic force spectroscopy data revealed that the 27apt's binding to the thrombin remains largely unaffected by the eight-spacer phosphoramidites within Bi-8S. In contrast, the eight-spacer phosphoramidites stabilized the 15apt-thrombin binding.
适体是一类用于蛋白质识别、检测和抑制的新型分子探针。通过适体组装实现多价适体-蛋白质结合，已被开发为一种有效提高蛋白质亲和力和选择性的方法。在本研究中，通过原子力显微镜直接和定量地测量了二价适体 Bi-8S 与凝血酶之间的特异性相互作用，以研究多价相互作用的解链动力学和离解能景观。二价适体 Bi-8S 包含凝血酶的两个适体 15apt 和 27apt，它们通过 8 个间隔臂膦酰胺连接。结果揭示了两个适体的顺序解离。此外，动态力谱数据显示，27apt 与凝血酶的结合在很大程度上不受 Bi-8S 内的 8 个间隔臂膦酰胺的影响。相比之下，8 个间隔臂膦酰胺稳定了 15apt-凝血酶的结合。
