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Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals
The NMR pulse sequence CODEX (centerband‐only detection of exchange) is a widely used method to report on the number of magnetically inequivalent spins that exchange magnetization via spin diffusion. For crystals, this rules out certain symmetries, and the rate of equilibration is sensitive to dista...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7497148/ https://www.ncbi.nlm.nih.gov/pubmed/32558171 http://dx.doi.org/10.1002/cphc.202000517 |
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author | Xue, Kai Dervisoglu, Riza Sowa, Heidrun Andreas, Loren B. |
author_facet | Xue, Kai Dervisoglu, Riza Sowa, Heidrun Andreas, Loren B. |
author_sort | Xue, Kai |
collection | PubMed |
description | The NMR pulse sequence CODEX (centerband‐only detection of exchange) is a widely used method to report on the number of magnetically inequivalent spins that exchange magnetization via spin diffusion. For crystals, this rules out certain symmetries, and the rate of equilibration is sensitive to distances. Here we show that for (13)C CODEX, consideration of natural abundance spins is necessary for crystals of high complexity, demonstrated here with the amino acid phenylalanine. The NMR data rule out the C(2) space group that was originally reported for phenylalanine, and are only consistent with a larger unit cell containing eight magnetically inequivalent molecules. Such an expanded cell was recently described based on single crystal data. The large unit cell dictates the use of long spin diffusion times of more than 200 seconds, in order to equilibrate over the entire unit cell volume of 1622 Å(3). |
format | Online Article Text |
id | pubmed-7497148 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-74971482020-09-25 Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals Xue, Kai Dervisoglu, Riza Sowa, Heidrun Andreas, Loren B. Chemphyschem Communications The NMR pulse sequence CODEX (centerband‐only detection of exchange) is a widely used method to report on the number of magnetically inequivalent spins that exchange magnetization via spin diffusion. For crystals, this rules out certain symmetries, and the rate of equilibration is sensitive to distances. Here we show that for (13)C CODEX, consideration of natural abundance spins is necessary for crystals of high complexity, demonstrated here with the amino acid phenylalanine. The NMR data rule out the C(2) space group that was originally reported for phenylalanine, and are only consistent with a larger unit cell containing eight magnetically inequivalent molecules. Such an expanded cell was recently described based on single crystal data. The large unit cell dictates the use of long spin diffusion times of more than 200 seconds, in order to equilibrate over the entire unit cell volume of 1622 Å(3). John Wiley and Sons Inc. 2020-07-13 2020-08-04 /pmc/articles/PMC7497148/ /pubmed/32558171 http://dx.doi.org/10.1002/cphc.202000517 Text en © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Communications Xue, Kai Dervisoglu, Riza Sowa, Heidrun Andreas, Loren B. Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title | Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title_full | Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title_fullStr | Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title_full_unstemmed | Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title_short | Centerband‐Only Detection of Exchange NMR with Natural‐Abundance Correction Reveals an Expanded Unit Cell in Phenylalanine Crystals |
title_sort | centerband‐only detection of exchange nmr with natural‐abundance correction reveals an expanded unit cell in phenylalanine crystals |
topic | Communications |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7497148/ https://www.ncbi.nlm.nih.gov/pubmed/32558171 http://dx.doi.org/10.1002/cphc.202000517 |
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