Catch-bond behavior of DNA condensate under tension*
Catch-bond behavior of DNA condensate under tension*
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DOI：
10.1088/1674-1056/24/12/128704
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发表时间：
2015-10
影响因子：
1.7
通讯作者：
Li Wei;Wong Wei-Juan;Lim Ci-Ji;Ju Hai-Peng;L. Ming;Yan Jie;Wang Peng-ye
中科院分区：
文献类型：
--
作者：
Li Wei;Wong Wei-Juan;Lim Ci-Ji;Ju Hai-Peng;L. Ming;Yan Jie;Wang Peng-ye
环状体的形成是DNA缩合的重要机制，已通过体外单分子实验进行了广泛的研究。利用磁镊技术结合布朗动力学模拟研究了DNA凝聚体的脱凝聚动力学。实验结果揭示了一个令人惊讶的非单调依赖性的展开速率对强粘附条件下施加的力，类似于在配体-受体相互作用领域中报道的捕获键行为。模拟结果表明，DNA凝聚体在外力作用下的不同展开路径来源于DNA环的力依赖性形变，这解释了DNA凝聚体在磁镊实验中的捕获键行为.这些结果挑战了常规环形DNA解缠机制的普遍性，并提供了迄今为止最完整的描述张力下的多价阳离子依赖的DNA解缠。
Toroid formation is an important mechanism underlying DNA condensation, which has been investigated extensively by single-molecule experiments in vitro. Here, the de-condensation dynamics of DNA condensates were studied using magnetic tweezers combined with Brownian dynamics simulations. The experimental results revealed a surprising non-monotonic dependence of the unfolding rate on the force applied under strong adhesion conditions, resembling the catch-bond behavior reported in the field of ligand-receptor interactions. Simulation results showed that the different unfolding pathways of DNA condensate under large forces derive from the force-dependent deformation of the DNA toroid, which explains the catch-bond behavior of DNA condensate in the magnetic tweezers experiments. These results challenge the universality of the regular toroidal DNA unwrapping mechanism and provide the most complete description to date of multivalent cation-dependent DNA unwrapping under tension.