Computation of the Mean First-Encounter Time Between the Ends of a Polymer Chain
Computation of the Mean First-Encounter Time Between the Ends of a Polymer Chain
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DOI：
10.1103/physrevlett.109.108302
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发表时间：
2012-09-05
影响因子：
8.6
通讯作者：
Holcman, D.
中科院分区：
文献类型：
--
作者：
Amitai, A.;Kupka, I.;Holcman, D.
Using a novel theoretical approach, we study the mean first-encounter time (MFET) between the two ends of a polymer. Previous approaches used various simplifications that reduced the complexity of the problem, leading, however, to incompatible results. We construct here for the first time a general theory that allows us to compute the MFET. The method is based on estimating the mean time for a Brownian particle to reach a narrow domain in the polymer configuration space. In dimension two and three, we find that the MFET depends mainly on the first eigenvalue of the associated Fokker-Planck operator and provide precise estimates that are confirmed by Brownian simulations. Interestingly, although many time scales are involved in the encounter process, its distribution can be well approximated by a single exponential, which has several consequences for modeling chromosome dynamics in the nucleus. Another application of our result is computing the mean time for a DNA molecule to form a closed loop (when its two ends meet for the first time).
