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 http://resolver.caltech.edu/CaltechAUTHORS:SEGprl06
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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.
|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.|
|Subject Keywords:||DNA; probability; molecular biophysics; biological techniques; macromolecules|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Lindsay Cleary|
|Deposited On:||02 Oct 2006|
|Last Modified:||26 Dec 2012 09:03|
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