DNA in a liquid‐crystalline environment: Tight bends, rings, supercoils
DNA in a liquid‐crystalline environment: Tight bends, rings, supercoils
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DOI：
10.1063/1.471966
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发表时间：
1996-07
影响因子：
4.4
通讯作者：
T. Odijk
中科院分区：
文献类型：
--
作者：
T. Odijk
紧密弯曲DNA的熵在各种问题中进行了研究：闭合概率，发夹形成，切口线圈，plectonemic超螺旋，所有这些都处于液晶有序状态。本文提出了一种新的半经典方法来导出紧曲蠕虫链的绿色函数。精确的估计所产生的熵起伏紧密弯曲的DNA在弱，中间，和强磁场。一个正式的统计力学分析概述了发夹和超螺旋。计算了在强磁场中无扭曲的封闭DNA的伸长。给出了一个无扭曲DNA环液晶的标度理论，其中DNA环的有序性和环的伸长是自洽耦合的。plectonemic超螺旋的伸长率进行评估，为弱和强磁场。一个plectonemic或松散的超螺旋的周期性阶段的音高被证明是直接关系到他们的扭动。
The entropy of tightly bent DNA is investigated in a variety of problems: closure probabilities, hairpin formation, nicked coils, plectonemic supercoiling, all in states with liquid‐crystalline order. A new semiclassical method is presented for deriving the Green function of a tightly curved wormlike chain. Precise estimates for the entropy arising from undulations are given for tightly bent DNA in weak, intermediate, and strong nematic fields. A formal statistical mechanical analysis is outlined for hairpins and supercoils. The elongation of closed DNA without twist is computed in strong nematic fields. A scaling theory is given for a liquid crystal of untwisted DNA rings in which nematic order and ring elongation are self‐consistently coupled. The elongation of plectonemic supercoils is evaluated for weak and strong nematic fields. The pitch of a cholesteric phase of plectonemic or loose supercoils is shown to be directly related to their writhe.