Fathizadeh A, Eslami-Mossallam B, Ejtehadi M R
Sharif University of Technology, Institue for Nanoscience and Nanotechnology, Post Office Box 14588-89694, Tehran, Iran.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Nov;86(5 Pt 1):051907. doi: 10.1103/PhysRevE.86.051907. Epub 2012 Nov 6.
By considering the detailed structure of DNA in the base pair level, two possible definitions of the persistence length are compared. One definition is related to the orientation of the terminal base pairs, and the other is based on the vectors which connect two adjacent base pairs at each end of the molecule. It is shown that although these definitions approach each other for long DNA molecules, they are dramatically different on short length scales. We show analytically that the difference mostly comes from the shear flexibility of the molecule and can be used to measure the shear modulus of DNA.
通过在碱基对层面考虑DNA的详细结构，比较了持续长度的两种可能定义。一种定义与末端碱基对的取向有关，另一种基于连接分子两端相邻碱基对的向量。结果表明，虽然对于长DNA分子这些定义相互接近，但在短长度尺度上它们有显著差异。我们通过分析表明，这种差异主要源于分子的剪切柔韧性，并且可用于测量DNA的剪切模量。
