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Long-lived metastable knots in polyampholyte chains
Knots in proteins and DNA are known to have significant effect on their equilibrium and dynamic properties as well as on their function. While knot dynamics and thermodynamics in electrically neutral and uniformly charged polymer chains are relatively well understood, proteins are generally polyamph...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10266668/ https://www.ncbi.nlm.nih.gov/pubmed/37315055 http://dx.doi.org/10.1371/journal.pone.0287200 |
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author | Ozmaian, Masoumeh Makarov, Dmitrii E. |
author_facet | Ozmaian, Masoumeh Makarov, Dmitrii E. |
author_sort | Ozmaian, Masoumeh |
collection | PubMed |
description | Knots in proteins and DNA are known to have significant effect on their equilibrium and dynamic properties as well as on their function. While knot dynamics and thermodynamics in electrically neutral and uniformly charged polymer chains are relatively well understood, proteins are generally polyampholytes, with varied charge distributions along their backbones. Here we use simulations of knotted polymer chains to show that variation in the charge distribution on a polyampholyte chain with zero net charge leads to significant variation in the resulting knot dynamics, with some charge distributions resulting in long-lived metastable knots that escape the (open-ended) chain on a timescale that is much longer than that for knots in electrically neutral chains. The knot dynamics in such systems can be described, quantitatively, using a simple one-dimensional model where the knot undergoes biased Brownian motion along a “reaction coordinate”, equal to the knot size, in the presence of a potential of mean force. In this picture, long-lived knots result from charge sequences that create large electrostatic barriers to knot escape. This model allows us to predict knot lifetimes even when those times are not directly accessible by simulations. |
format | Online Article Text |
id | pubmed-10266668 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-102666682023-06-15 Long-lived metastable knots in polyampholyte chains Ozmaian, Masoumeh Makarov, Dmitrii E. PLoS One Research Article Knots in proteins and DNA are known to have significant effect on their equilibrium and dynamic properties as well as on their function. While knot dynamics and thermodynamics in electrically neutral and uniformly charged polymer chains are relatively well understood, proteins are generally polyampholytes, with varied charge distributions along their backbones. Here we use simulations of knotted polymer chains to show that variation in the charge distribution on a polyampholyte chain with zero net charge leads to significant variation in the resulting knot dynamics, with some charge distributions resulting in long-lived metastable knots that escape the (open-ended) chain on a timescale that is much longer than that for knots in electrically neutral chains. The knot dynamics in such systems can be described, quantitatively, using a simple one-dimensional model where the knot undergoes biased Brownian motion along a “reaction coordinate”, equal to the knot size, in the presence of a potential of mean force. In this picture, long-lived knots result from charge sequences that create large electrostatic barriers to knot escape. This model allows us to predict knot lifetimes even when those times are not directly accessible by simulations. Public Library of Science 2023-06-14 /pmc/articles/PMC10266668/ /pubmed/37315055 http://dx.doi.org/10.1371/journal.pone.0287200 Text en © 2023 Ozmaian, Makarov https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Ozmaian, Masoumeh Makarov, Dmitrii E. Long-lived metastable knots in polyampholyte chains |
title | Long-lived metastable knots in polyampholyte chains |
title_full | Long-lived metastable knots in polyampholyte chains |
title_fullStr | Long-lived metastable knots in polyampholyte chains |
title_full_unstemmed | Long-lived metastable knots in polyampholyte chains |
title_short | Long-lived metastable knots in polyampholyte chains |
title_sort | long-lived metastable knots in polyampholyte chains |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10266668/ https://www.ncbi.nlm.nih.gov/pubmed/37315055 http://dx.doi.org/10.1371/journal.pone.0287200 |
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