Velizhanin Kirill A, Chien Chih-Chun, Dubi Yonatan, Zwolak Michael
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 1):050906. doi: 10.1103/PhysRevE.83.050906. Epub 2011 May 19.
DNA denaturation has been a subject of intense study due to its relationship to DNA transcription and its fundamental importance as a nonlinear structural transition. Many aspects of this phenomenon, however, remain poorly understood. Existing models fit quite well with experimental results on the fraction of unbound base pairs versus temperature, but yield incorrect results for other essential quantities such as the base pair fluctuation time scales. Here we demonstrate that nanoscale thermal transport can serve as a sensitive probe of the underlying microscopic physics responsible for the dynamics of DNA denaturation. Specifically, we show that the heat transport properties of DNA are altered significantly as it denatures, and this alteration encodes detailed information on the dynamics of thermal fluctuations and their interaction along the strand. This finding allows for the discrimination between models of DNA denaturation and will help shed new light on the nonlinear vibrational dynamics of this important molecule.
由于DNA变性与DNA转录相关，且作为一种非线性结构转变具有根本重要性，因此它一直是深入研究的主题。然而，这一现象的许多方面仍知之甚少。现有模型与未结合碱基对比例与温度关系的实验结果拟合得相当好，但对于其他重要量，如碱基对波动时间尺度，却得出了错误结果。在这里，我们证明纳米尺度的热输运可以作为一种敏感探针，用于探测导致DNA变性动力学的潜在微观物理过程。具体而言，我们表明DNA变性时其热输运性质会发生显著改变，这种改变编码了关于热涨落动力学及其沿链相互作用的详细信息。这一发现有助于区分DNA变性模型，并将有助于为这一重要分子的非线性振动动力学带来新的启示。
