Biomolecular Science and Engineering Program, University of California, Santa Barbara, California, USA.
Biophys J. 2012 Jan 4;102(1):96-100. doi: 10.1016/j.bpj.2011.11.4014. Epub 2012 Jan 3.
During a variety of biological and technological processes, biopolymers are simultaneously subject to both confinement and external forces. Although significant efforts have gone into understanding the physics of polymers that are only confined, or only under tension, little work has been done to explore the effects of the interplay of force and confinement. Here, we study the combined effects of stretching and confinement on a polymer's configurational freedom. We measure the elastic response of long double-stranded DNA molecules that are partially confined to thin, nanofabricated slits. We account for the data through a model in which the DNA's short-wavelength transverse elastic modes are cut off by applied force and the DNA's bending stiffness, whereas long-wavelength modes are cut off by confinement. Thus, we show that confinement and stretching combine to permit tunable bandpass filtering of the elastic modes of long polymers.
在各种生物和技术过程中，生物聚合物同时受到限制和外部力的作用。虽然已经做出了很大的努力来理解仅受限制或仅受张力的聚合物的物理学，但很少有工作用于探索力和限制相互作用的影响。在这里，我们研究了拉伸和限制对聚合物构象自由度的综合影响。我们测量了部分限制在薄的纳米制造狭缝中的长双链 DNA 分子的弹性响应。我们通过一个模型来解释这些数据，该模型中，施加的力会切断 DNA 的短波长横向弹性模式，而 DNA 的弯曲刚度则会切断长波长模式。因此，我们表明，限制和拉伸相结合，可以对长聚合物的弹性模式进行可调谐的带通滤波。
