Revisiting blob theory for DNA diffusivity in slitlike confinement.
Revisiting blob theory for DNA diffusivity in slitlike confinement.
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DOI：
10.1103/physrevlett.110.168105
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发表时间：
2013-04-19
影响因子：
8.6
通讯作者：
Doyle PS
中科院分区：
文献类型：
--
作者：
Dai L;Tree DR;van der Maarel JR;Dorfman KD;Doyle PS
Blob理论已被广泛应用于描述聚合物的构象和动力学的纳米约束。在狭缝限制，斑点理论预测的缩放指数为2/3的聚合物扩散作为狭缝高度的函数，但大量的实验研究使用DNA产生的缩放指数显着小于2/3。在这项工作中，我们开发了一种理论，预测这种差异的发生，因为段相关函数的半柔性链，如DNA不遵循弗洛里指数的长度尺度小于持久性长度。我们发现，这些短的长度尺度效应有助于显着的DNA扩散率的缩放，但不明显影响静态性能的缩放。我们的理论是完全支持Monte Carlo模拟，定量协议与DNA实验，结果调和这个突出的问题，限制聚合物。
Blob theory has been widely applied to describe polymer conformations and dynamics in nanoconfinement. In slit confinement, blob theory predicts a scaling exponent of 2/3 for polymer diffusivity as a function of slit height, yet a large body of experimental studies using DNA produce a scaling exponent significantly less than 2/3. In this work, we develop a theory that predicts that this discrepancy occurs because the segment correlation function for a semiflexible chain such as DNA does not follow the Flory exponent for length scales smaller than the persistence length. We show that these short length scale effects contribute significantly to the scaling for the DNA diffusivity, but do not appreciably affect the scalings for static properties. Our theory is fully supported by Monte Carlo simulations, quantitative agreement with DNA experiments, and the results reconcile this outstanding problem for confined polymers.