Volume 116, Number 6, December 2016
|Number of page(s)||6|
|Section||Interdisciplinary Physics and Related Areas of Science and Technology|
|Published online||14 February 2017|
Force responses of strongly intrinsically curved DNA helices deviate from worm-like chain predictions
1 Lorentz Institute, Leiden University - Niels Bohrweg 2, 2333CA Leiden, The Netherlands
2 Department of Information and Computing Sciences, Utrecht University - Princetonplein 5, 3584CC Utrecht, The Netherlands
Received: 1 November 2016
Accepted: 20 January 2017
DNA sequences with nontrivial intrinsic curvature are of interest for a range of biological and artificial DNA systems. We design both intrinsically strongly curved and intrinsically straight sequences. We find that such sequences with opposing curvatures can be designed even under constraints that would naively lead one to assume that those sequences would be highly similar in their mechanical properties. We then characterize the force response of those sequences and find that their force-extension curves deviate significantly in the low-force regime, and that the standard worm-like chain description is inadequate to describe the low-force response of the strongly bent sequences. We propose a modified description that takes the intrinsic curvature into account, making the DNA act, in the low-force regime, like a nanoscale helical spring. We find strongly improved agreement between the model and the simulated force-extension curves.
PACS: 87.14.gk – DNA / 87.15.La – Mechanical properties / 87.15.Qt – Sequence analysis
© EPLA, 2016
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