Department of Physics Papers
Document Type
Journal Article
Date of this Version
7-1997
Publication Source
European Physical Journal B
Volume
1
Issue
1
Start Page
95
Last Page
102
DOI
10.1007/s100510050156
Abstract
We present an elastic model of B-form DNA as a stack of thin, rigid plates or base pairs that are not permitted to deform. The symmetry of DNA and the constraint of plate rigidity limit the number of bulk elastic constants contributing to a macroscopic elasticity theory of DNA to four. We derive an effective twist-stretch energy in terms of the macroscopic stretch ǫ along and relative excess twist σ about the DNA molecular axis. In addition to the bulk stretch and twist moduli found previously, we obtain a twist-stretch modulus with the following remarkable properties: 1) it vanishes when the radius of the helical curve following the geometric center of each plate is zero, 2) it vanishes with the elastic constant K23 that couples compression normal to the plates to a shear strain, if the plates are perpendicular to the molecular axis, and 3) it is nonzero if the plates are tilted relative to the molecular axis. This implies that a laminated helical structure carved out of an isotropic elastic medium will not twist in response to a stretching force, but an isotropic material will twist if it is bent into the shape of a helix.
Copyright/Permission Statement
This is a pre-publication version of the final printed paper: dx.doi.org/10.1007/s100510050156.
Recommended Citation
O'Hern, C. S., Kamien, R., Lubensky, T. C., & Nelson, P. C. (1997). Elasticity Theory of a Twisted Stack of Plates. European Physical Journal B, 1 (1), 95-102. http://dx.doi.org/10.1007/s100510050156
Date Posted: 15 March 2017
This document has been peer reviewed.