Direct observation of large temperature fluctuations during DNA thermal denaturation.
Direct observation of large temperature fluctuations during DNA thermal denaturation.
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直接观察 DNA 热变性过程中的大温度波动。
DOI：
10.1103/physrevlett.96.038102
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发表时间：
2005
影响因子：
8.6
通讯作者：
D. Chatterji
中科院分区：
文献类型：
--
作者：
K. S. Nagapriya;A. Raychaudhuri;D. Chatterji
在这封信中，我们报告了双链 DNA 在经历变性转变时的大低频温度波动的直接测量。这种波动仅发生在发生变性的温度范围内，比预期的平衡波动大几个数量级。它在相同序列的单链DNA中不存在。给定温度下的波动还取决于等待时间，并在几个小时内消失。这表明，大波动的发生是由于共存的变性和闭合碱基对，由于通过25-30kBT0（T0=300 K）规模的势垒的转变而处于动态平衡。
In this Letter, we report direct measurement of large low frequency temperature fluctuations in double stranded DNA when it undergoes a denaturation transition. The fluctuation, which occurs only in the temperature range where the denaturation occurs, is several orders more than the expected equilibrium fluctuation. It is absent in single stranded DNA of the same sequence. The fluctuation at a given temperature also depends on the wait time and vanishes in a scale of a few hours. It is suggested that the large fluctuation occurs due to coexisting denaturated and closed base pairs that are in dynamic equilibrium due to the transition through a potential barrier in the scale of 25-30kBT0 (T0=300 K).