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Characterizing Fast Conformational Exchange of Aromatic Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips from Other Exchange Mechanisms
[Image: see text] Aromatic ring flips are a hallmark of protein dynamics. They are experimentally studied by NMR spectroscopy, where recent advances have led to improved characterization across a wide range of time scales. Results on different proteins have been interpreted as continuous diffusive r...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2022
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9574926/ https://www.ncbi.nlm.nih.gov/pubmed/36180044 http://dx.doi.org/10.1021/acs.jpcb.2c05097 |
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author | Dreydoppel, Matthias Akke, Mikael Weininger, Ulrich |
author_facet | Dreydoppel, Matthias Akke, Mikael Weininger, Ulrich |
author_sort | Dreydoppel, Matthias |
collection | PubMed |
description | [Image: see text] Aromatic ring flips are a hallmark of protein dynamics. They are experimentally studied by NMR spectroscopy, where recent advances have led to improved characterization across a wide range of time scales. Results on different proteins have been interpreted as continuous diffusive ring rotations or jumplike flips, leading to diverging views of the protein interior as being fluidlike or solidlike, respectively. It is challenging to distinguish between these mechanisms and other types of conformational exchange because chemical-shift-mediated line broadening provides only conclusive evidence for ring flips only if the system can be moved from the slow- to intermediate/fast-exchange regime. Moreover, whenever the chemical shift difference between the two symmetry-related sites is close to zero, it is not generally possible to determine the exchange time scale. Here we resolve these issues by measuring residual dipolar coupling (RDC)-mediated exchange contributions using NMR relaxation dispersion experiments on proteins dissolved in dilute liquid crystalline media. Excellent agreement is found between the experimental difference in RDC between the two symmetry-related sites and the value calculated from high-resolution X-ray structures, demonstrating that dynamics measured for F52 in the B1 domain of protein G reports on distinct, jumplike flips rather than other types of conformational exchange. |
format | Online Article Text |
id | pubmed-9574926 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-95749262022-10-18 Characterizing Fast Conformational Exchange of Aromatic Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips from Other Exchange Mechanisms Dreydoppel, Matthias Akke, Mikael Weininger, Ulrich J Phys Chem B [Image: see text] Aromatic ring flips are a hallmark of protein dynamics. They are experimentally studied by NMR spectroscopy, where recent advances have led to improved characterization across a wide range of time scales. Results on different proteins have been interpreted as continuous diffusive ring rotations or jumplike flips, leading to diverging views of the protein interior as being fluidlike or solidlike, respectively. It is challenging to distinguish between these mechanisms and other types of conformational exchange because chemical-shift-mediated line broadening provides only conclusive evidence for ring flips only if the system can be moved from the slow- to intermediate/fast-exchange regime. Moreover, whenever the chemical shift difference between the two symmetry-related sites is close to zero, it is not generally possible to determine the exchange time scale. Here we resolve these issues by measuring residual dipolar coupling (RDC)-mediated exchange contributions using NMR relaxation dispersion experiments on proteins dissolved in dilute liquid crystalline media. Excellent agreement is found between the experimental difference in RDC between the two symmetry-related sites and the value calculated from high-resolution X-ray structures, demonstrating that dynamics measured for F52 in the B1 domain of protein G reports on distinct, jumplike flips rather than other types of conformational exchange. American Chemical Society 2022-09-30 2022-10-13 /pmc/articles/PMC9574926/ /pubmed/36180044 http://dx.doi.org/10.1021/acs.jpcb.2c05097 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by-nc-nd/4.0/Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Dreydoppel, Matthias Akke, Mikael Weininger, Ulrich Characterizing Fast Conformational Exchange of Aromatic Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips from Other Exchange Mechanisms |
title | Characterizing
Fast Conformational Exchange of Aromatic
Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips
from Other Exchange Mechanisms |
title_full | Characterizing
Fast Conformational Exchange of Aromatic
Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips
from Other Exchange Mechanisms |
title_fullStr | Characterizing
Fast Conformational Exchange of Aromatic
Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips
from Other Exchange Mechanisms |
title_full_unstemmed | Characterizing
Fast Conformational Exchange of Aromatic
Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips
from Other Exchange Mechanisms |
title_short | Characterizing
Fast Conformational Exchange of Aromatic
Rings Using Residual Dipolar Couplings: Distinguishing Jumplike Flips
from Other Exchange Mechanisms |
title_sort | characterizing
fast conformational exchange of aromatic
rings using residual dipolar couplings: distinguishing jumplike flips
from other exchange mechanisms |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9574926/ https://www.ncbi.nlm.nih.gov/pubmed/36180044 http://dx.doi.org/10.1021/acs.jpcb.2c05097 |
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