Skip to main content
Journal cover image

Single-stranded nucleic acid elasticity arises from internal electrostatic tension

Publication ,  Journal Article
Jacobson, DR; McIntosh, DB; Stevens, MJ; Rubinstein, M; Saleh, OA
Published in: Proceedings of the National Academy of Sciences
2017

Understanding of the conformational ensemble of flexible polyelectrolytes, such as single-stranded nucleic acids (ssNAs), is complicated by the interplay of chain backbone entropy and salt-dependent electrostatic repulsions. Molecular elasticity measurements are sensitive probes of the statistical conformation of polymers and have elucidated ssNA conformation at low force, where electrostatic repulsion leads to a strong excluded volume effect, and at high force, where details of the backbone structure become important. Here, we report measurements of ssDNA and ssRNA elasticity in the intermediate-force regime, corresponding to 5- to 100-pN forces and 50-85% extension. These data are explained by a modified wormlike chain model incorporating an internal electrostatic tension. Fits to the elastic data show that the internal tension decreases with salt, from [Formula: see text]5 pN under 5 mM ionic strength to near zero at 1 M. This decrease is quantitatively described by an analytical model of electrostatic screening that ascribes to the polymer an effective charge density that is independent of force and salt. Our results thus connect microscopic chain physics to elasticity and structure at intermediate scales and provide a framework for understanding flexible polyelectrolyte elasticity across a broad range of relative extensions.

Duke Scholars

Altmetric Attention Stats
Dimensions Citation Stats

Published In

Proceedings of the National Academy of Sciences

DOI

ISSN

0027-8424

Publication Date

2017
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Jacobson, D. R., McIntosh, D. B., Stevens, M. J., Rubinstein, M., & Saleh, O. A. (2017). Single-stranded nucleic acid elasticity arises from internal electrostatic tension. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1701132114
Jacobson, David R., Dustin B. McIntosh, Mark J. Stevens, Michael Rubinstein, and Omar A. Saleh. “Single-stranded nucleic acid elasticity arises from internal electrostatic tension.” Proceedings of the National Academy of Sciences, 2017. https://doi.org/10.1073/pnas.1701132114.
Jacobson DR, McIntosh DB, Stevens MJ, Rubinstein M, Saleh OA. Single-stranded nucleic acid elasticity arises from internal electrostatic tension. Proceedings of the National Academy of Sciences. 2017;
Jacobson, David R., et al. “Single-stranded nucleic acid elasticity arises from internal electrostatic tension.” Proceedings of the National Academy of Sciences, 2017. Manual, doi:10.1073/pnas.1701132114.
Jacobson DR, McIntosh DB, Stevens MJ, Rubinstein M, Saleh OA. Single-stranded nucleic acid elasticity arises from internal electrostatic tension. Proceedings of the National Academy of Sciences. 2017;
Journal cover image

Published In

Proceedings of the National Academy of Sciences

DOI

ISSN

0027-8424

Publication Date

2017