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Volume-exclusion effects in tethered-particle experiments: bead size matters

Segall, Darren E. and Nelson, Philip C. and Phillips, Rob (2006) Volume-exclusion effects in tethered-particle experiments: bead size matters. Physical Review Letters, 96 (8). Art. No. 088306. ISSN 0031-9007. PMCID PMC3261840. doi:10.1103/PhysRevLett.96.088306.

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We give a theoretical analysis of bead motion in tethered-particle experiments, a single-molecule technique that has been used to explore the dynamics of a variety of macromolecules of biological interest. Our analysis reveals that the proximity of the tethered bead to a nearby surface gives rise to a volume-exclusion effect, resulting in an entropic stretching-force on the molecule that changes its statistical properties. In addition, volume exclusion brings about intriguing scaling relations between key observables (statistical moments of the bead) and parameters such as bead size and contour length of the molecule. We present analytic and numerical results for these effects in both flexible and semiflexible tethers. Finally, our results give a precise, experimentally testable prediction for the probability distribution of the bead center measured from the polymer attachment point.

Item Type:Article
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URLURL TypeDescription CentralArticle
Phillips, Rob0000-0003-3082-2809
Alternate Title:Excluded-Volume Effects in Tethered-Particle Experiments: Bead Size Matters
Additional Information:© 2006 The American Physical Society. Received 20 August 2005; published 3 March 2006. We thank J. Beausang, S. Blumberg, D. Brogioli, D. Chow, D. Dunlap, L. Finzi, J. Gelles, Y. Goldman, I. Kulic, J.C. Meiners, T. Perkins, P. Purohit, F. Vanzi, P. Wiggins, C. Zurla, for extensive discussions. D.S. acknowledges the support of AFOSR/DARPA Grant No. F49620-02-1-0085. R.P. acknowledges the support of the NIH Grant No. DP1 OD000217 and NSF Grant No. CMS-0301657. P.N. acknowledges the Human Frontier Science Foundation and NSF Grants No. DMR-0425780 and No. DMR-0404674.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Air Force Office of Scientific Research (AFOSR)F49620-02-1-0085
NIHDP1 OD000217
Human Frontier Science ProgramUNSPECIFIED
Subject Keywords:DNA; probability; molecular biophysics; biological techniques; macromolecules
Issue or Number:8
PubMed Central ID:PMC3261840
Record Number:CaltechAUTHORS:SEGprl06
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5123
Deposited By: Lindsay Cleary
Deposited On:02 Oct 2006
Last Modified:08 Nov 2021 20:22

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