Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
Biochemistry (Mosc). 2022 Nov;87(11):1292-1300. doi: 10.1134/S0006297922110086.
The process of unfolding of G-quadruplex structure in the RE31 DNA-aptamer and in its complex with thrombin under the action of the fluorescently labeled complementary oligonucleotides of varying length with formation of double-helix structures has been studied. It has been suggested that G-quadruplex unfolding involves formation of an intermediate complex with an oligonucleotide. Thermodynamic parameters and kinetics of unfolding of the free aptamer and its complex with thrombin differ. Extension of the oligonucleotide sequence complementary to G-quadruplex by two nucleotides to cover the so-called "hinge region" had little impact on the conformational transition of G-quadruplex of the free aptamer. However, a pronounced effect has been observed for the aptamer-protein complex. Most likely these differences could be explained by the thrombin-induced conformational transition of the aptamer involving the hinge region.
已经研究了在荧光标记的不同长度的互补寡核苷酸的作用下，RE31 DNA-适体及其与凝血酶的复合物中 G-四链体结构的展开过程，形成了双链结构。已经表明，G-四链体的展开涉及与寡核苷酸形成中间复合物。游离适体及其与凝血酶复合物的解折叠热力学参数和动力学不同。通过将与 G-四链体互补的寡核苷酸序列延伸两个核苷酸以覆盖所谓的“铰链区域”，对游离适体的 G-四链体构象转变几乎没有影响。然而，对于适体-蛋白质复合物观察到了明显的效果。这些差异很可能可以通过涉及铰链区域的凝血酶诱导的适体构象转变来解释。
