Chemistry Department M.V. Lomonosov Moscow State University, Leninskie gory 1-3, Moscow, 119991 Russian Federation, Russia.
Curr Med Chem. 2013;20(38):4836-43. doi: 10.2174/09298673113206660283.
G-quadruplex based DNA aptamers for human thrombin are promising pharmaceuticals as anticoagulants. Initially discovered 15-mer DNA aptamer (15-TBA) has a minimal G-quadruplex structure which is able to inhibit thrombin. 15-TBA was modified and extended to improve aptamer activity and in vivo stability providing 31-TBA, NU172, RA-36, and some others as successful examples. In this paper an interplay between G-quadruplex (pharmacophore module) and additional modules has been studied. An original turbidimetric assay and conventional coagulation tests were applied to evaluate both inhibitory activity and type of inhibiting for aptamers constructed by exchanging the modules between 31- TBA and NU172. Additional modules strongly affect pharmacophore module inhibitory activity either enhancing or reducing it. RA-36 aptamer has two putative pharmacophore entities which also interplay being functionally non-equal. 5'- truncated RA-36 has half of the activity of RA-36, and the same as for 15-TBA. On the contrary 3'-truncated RA-36 has intermediate activity in between 15-TBA and RA-36. These results indicate fine regulation of G-quadruplex inhibitory activity by additional modules, as well as non-trivial behavior of joined pharmacophore modules.
基于 G-四链体的人凝血酶 DNA 适体作为抗凝剂具有广阔的应用前景。最初发现的 15 个碱基 DNA 适体（15-TBA）具有最小的 G-四链体结构，能够抑制凝血酶。15-TBA 经过修饰和扩展，以提高适体的活性和体内稳定性，提供了 31-TBA、NU172、RA-36 等成功的例子。本文研究了 G-四链体（药效团模块）和附加模块之间的相互作用。应用原始浊度测定法和常规凝血试验评估了在 31-TBA 和 NU172 之间交换模块构建的适体的抑制活性和抑制类型。附加模块强烈影响药效团模块的抑制活性，增强或降低其活性。RA-36 适体有两个假定的药效团实体，它们也相互作用，功能上不等同。5'-截断的 RA-36 的活性只有 RA-36 的一半，与 15-TBA 相同。相反，3'-截断的 RA-36 的活性介于 15-TBA 和 RA-36 之间。这些结果表明附加模块对 G-四链体抑制活性的精细调节，以及药效团模块的非平凡行为。
