Force-induced unfolding of human telomeric G-quadruplex: A steered molecular dynamics simulation study
Force-induced unfolding of human telomeric G-quadruplex: A steered molecular dynamics simulation study
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DOI：
10.1016/j.bbrc.2008.12.006
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发表时间：
2009-01-30
影响因子：
3.1
通讯作者：
Gisler, Thomas
中科院分区：
文献类型：
--
作者：
Li, Hui;Cao, En-hua;Gisler, Thomas
We Study the unfolding of a parallel G-quadruplex from human telomeric DNA by mechanical stretching using steered molecular dynamics (MD) simulation. We find that the force curves and unfolding processes strongly depend oil the pulling sites. With pulling sites located on the sugar-phosphate backbone, the force-extension Curve shows a single peak and the unfolding proceeds sequentially. Pulling sites located on the terminal nucleobases lead to a force-extension Curve with two peaks and the unfolding is more cooperative. Simulations of the refolding of partially unfolded quadruplexes show very different behavior for the two different Pulling modalities. In particular, starting from an unfolded state prepared by nucleobase pulling leads to a long-lived intermediate state whose existence is also corroborated by the free energy profile computed with the Jarzynski equation. Based on this observation, we propose a novel folding pathway for parallel G-quadruplexes with the human telomere sequence. (C) 2008 Elsevier Inc. All rights reserved.
