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Effects of Crowding on the Stability of a Surface-Tethered Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime
[Image: see text] The high packing densities and fixed geometries with which biomolecules can be attached to macroscopic surfaces suggest that crowding effects may be particularly significant under these often densely packed conditions. Exploring this question experimentally, we report here the effe...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2014
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4091282/ https://www.ncbi.nlm.nih.gov/pubmed/24919057 http://dx.doi.org/10.1021/ja411486g |
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author | Watkins, Herschel M. Simon, Anna J. Ricci, Francesco Plaxco, Kevin W. |
author_facet | Watkins, Herschel M. Simon, Anna J. Ricci, Francesco Plaxco, Kevin W. |
author_sort | Watkins, Herschel M. |
collection | PubMed |
description | [Image: see text] The high packing densities and fixed geometries with which biomolecules can be attached to macroscopic surfaces suggest that crowding effects may be particularly significant under these often densely packed conditions. Exploring this question experimentally, we report here the effects of crowding on the stability of a simple, surface-attached DNA stem-loop. We find that crowding by densely packed, folded biomolecules destabilizes our test-bed biomolecule by ∼2 kJ/mol relative to the dilute (noninteracting) regime, an effect that presumably occurs due to steric and electrostatic repulsion arising from compact neighbors. Crowding by a dense brush of unfolded biomolecules, in contrast, enhances its stability by ∼6 kJ/mol, presumably due to excluded volume and electrostatic effects that reduce the entropy of the unfolded state. Finally, crowding by like copies of the same biomolecule produces a significantly broader unfolding transition, likely because, under these circumstances, the stabilizing effects of crowding by unfolded molecules increase (and the destabilizing effects of neighboring folded molecules decrease) as more and more neighbors unfold. The crowding of surface-attached biomolecules may thus be a richer, more complex phenomenon than that seen in homogeneous solution. |
format | Online Article Text |
id | pubmed-4091282 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | American Chemical
Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-40912822015-06-11 Effects of Crowding on the Stability of a Surface-Tethered Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime Watkins, Herschel M. Simon, Anna J. Ricci, Francesco Plaxco, Kevin W. J Am Chem Soc [Image: see text] The high packing densities and fixed geometries with which biomolecules can be attached to macroscopic surfaces suggest that crowding effects may be particularly significant under these often densely packed conditions. Exploring this question experimentally, we report here the effects of crowding on the stability of a simple, surface-attached DNA stem-loop. We find that crowding by densely packed, folded biomolecules destabilizes our test-bed biomolecule by ∼2 kJ/mol relative to the dilute (noninteracting) regime, an effect that presumably occurs due to steric and electrostatic repulsion arising from compact neighbors. Crowding by a dense brush of unfolded biomolecules, in contrast, enhances its stability by ∼6 kJ/mol, presumably due to excluded volume and electrostatic effects that reduce the entropy of the unfolded state. Finally, crowding by like copies of the same biomolecule produces a significantly broader unfolding transition, likely because, under these circumstances, the stabilizing effects of crowding by unfolded molecules increase (and the destabilizing effects of neighboring folded molecules decrease) as more and more neighbors unfold. The crowding of surface-attached biomolecules may thus be a richer, more complex phenomenon than that seen in homogeneous solution. American Chemical Society 2014-06-11 2014-06-25 /pmc/articles/PMC4091282/ /pubmed/24919057 http://dx.doi.org/10.1021/ja411486g Text en Copyright © 2014 American Chemical Society Terms of Use (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) |
spellingShingle | Watkins, Herschel M. Simon, Anna J. Ricci, Francesco Plaxco, Kevin W. Effects of Crowding on the Stability of a Surface-Tethered Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title | Effects
of Crowding on the Stability of a Surface-Tethered
Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title_full | Effects
of Crowding on the Stability of a Surface-Tethered
Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title_fullStr | Effects
of Crowding on the Stability of a Surface-Tethered
Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title_full_unstemmed | Effects
of Crowding on the Stability of a Surface-Tethered
Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title_short | Effects
of Crowding on the Stability of a Surface-Tethered
Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime |
title_sort | effects
of crowding on the stability of a surface-tethered
biopolymer: an experimental study of folding in a highly crowded regime |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4091282/ https://www.ncbi.nlm.nih.gov/pubmed/24919057 http://dx.doi.org/10.1021/ja411486g |
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