不同水合水平下DNA中的缓慢弛豫过程。
Slow relaxation process in DNA at different levels of hydration.
作者信息
Sokolov A P, Grimm H, Kisliuk A, Dianoux A J
机构信息
Department of Polymer Science, University of Akron, Akron, OH 44325-3909 USA.
出版信息
J Biol Phys. 2000 Sep;26(3):1-5. doi: 10.1023/A:1010368332605.
There are many speculations about the dynamic transition observed in hydrated bio-polymers at temperatures T ∼ 200 - 230 K being an important factor for enabling of their functions. The transition shows up as a sharp increase of atomic mean-squared displacements above this temperature. The nature of the dynamic transition is not yet clear. Using inelastic neutron scattering we show in this Note that the transition in DNA is related to the appearance of a slow relaxation process. Decrease in the hydration level suppresses the process and the dynamic transition. It is found that, in terms of dynamics, the decrease in water content is similar in effect to a decrease in temperature. The obtained results support the idea that the dynamic transition is mediated by the water of hydration since bulk water has a dynamic transition around the same temperature.
关于在温度T ∼ 200 - 230 K时在水合生物聚合物中观察到的动态转变是其功能实现的重要因素，存在许多推测。这种转变表现为在此温度以上原子均方位移的急剧增加。动态转变的本质尚不清楚。在本笔记中，我们利用非弹性中子散射表明，DNA中的转变与一种缓慢弛豫过程的出现有关。水合水平的降低会抑制该过程以及动态转变。研究发现，就动力学而言，含水量的降低在效果上类似于温度的降低。所得结果支持了动态转变是由水合水介导的这一观点，因为大量水在大致相同的温度附近有一个动态转变。
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