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Electrospray ionization of native membrane proteins proceeds via a charge equilibration step
Electrospray ionization mass spectrometry is increasingly applied to study the structures and interactions of membrane protein complexes. However, the charging mechanism is complicated by the presence of detergent micelles during ionization. Here, we show that the final charge of membrane proteins c...
Autores principales: | , , , , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8972943/ https://www.ncbi.nlm.nih.gov/pubmed/35424940 http://dx.doi.org/10.1039/d2ra01282k |
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author | Yen, Hsin-Yung Abramsson, Mia L. Agasid, Mark T. Lama, Dilraj Gault, Joseph Liko, Idlir Kaldmäe, Margit Saluri, Mihkel Qureshi, Abdul Aziz Suades, Albert Drew, David Degiacomi, Matteo T. Marklund, Erik G. Allison, Timothy M. Robinson, Carol V. Landreh, Michael |
author_facet | Yen, Hsin-Yung Abramsson, Mia L. Agasid, Mark T. Lama, Dilraj Gault, Joseph Liko, Idlir Kaldmäe, Margit Saluri, Mihkel Qureshi, Abdul Aziz Suades, Albert Drew, David Degiacomi, Matteo T. Marklund, Erik G. Allison, Timothy M. Robinson, Carol V. Landreh, Michael |
author_sort | Yen, Hsin-Yung |
collection | PubMed |
description | Electrospray ionization mass spectrometry is increasingly applied to study the structures and interactions of membrane protein complexes. However, the charging mechanism is complicated by the presence of detergent micelles during ionization. Here, we show that the final charge of membrane proteins can be predicted by their molecular weight when released from the non-charge reducing saccharide detergents. Our data indicate that PEG detergents lower the charge depending on the number of detergent molecules in the surrounding micelle, whereas fos-choline detergents may additionally participate in ion–ion reactions after desolvation. The supercharging reagent sulfolane, on the other hand, has no discernible effect on the charge of detergent-free membrane proteins. Taking our observations into the context of protein-detergent interactions in the gas phase, we propose a charge equilibration model for the generation of native-like membrane protein ions. During ionization of the protein-detergent complex, the ESI charges are distributed between detergent and protein according to proton affinity of the detergent, number of detergent molecules, and surface area of the protein. Charge equilibration influenced by detergents determines the final charge state of membrane proteins. This process likely contributes to maintaining a native-like fold after detergent release and can be harnessed to stabilize particularly labile membrane protein complexes in the gas phase. |
format | Online Article Text |
id | pubmed-8972943 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | The Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-89729432022-04-13 Electrospray ionization of native membrane proteins proceeds via a charge equilibration step Yen, Hsin-Yung Abramsson, Mia L. Agasid, Mark T. Lama, Dilraj Gault, Joseph Liko, Idlir Kaldmäe, Margit Saluri, Mihkel Qureshi, Abdul Aziz Suades, Albert Drew, David Degiacomi, Matteo T. Marklund, Erik G. Allison, Timothy M. Robinson, Carol V. Landreh, Michael RSC Adv Chemistry Electrospray ionization mass spectrometry is increasingly applied to study the structures and interactions of membrane protein complexes. However, the charging mechanism is complicated by the presence of detergent micelles during ionization. Here, we show that the final charge of membrane proteins can be predicted by their molecular weight when released from the non-charge reducing saccharide detergents. Our data indicate that PEG detergents lower the charge depending on the number of detergent molecules in the surrounding micelle, whereas fos-choline detergents may additionally participate in ion–ion reactions after desolvation. The supercharging reagent sulfolane, on the other hand, has no discernible effect on the charge of detergent-free membrane proteins. Taking our observations into the context of protein-detergent interactions in the gas phase, we propose a charge equilibration model for the generation of native-like membrane protein ions. During ionization of the protein-detergent complex, the ESI charges are distributed between detergent and protein according to proton affinity of the detergent, number of detergent molecules, and surface area of the protein. Charge equilibration influenced by detergents determines the final charge state of membrane proteins. This process likely contributes to maintaining a native-like fold after detergent release and can be harnessed to stabilize particularly labile membrane protein complexes in the gas phase. The Royal Society of Chemistry 2022-04-01 /pmc/articles/PMC8972943/ /pubmed/35424940 http://dx.doi.org/10.1039/d2ra01282k Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/ |
spellingShingle | Chemistry Yen, Hsin-Yung Abramsson, Mia L. Agasid, Mark T. Lama, Dilraj Gault, Joseph Liko, Idlir Kaldmäe, Margit Saluri, Mihkel Qureshi, Abdul Aziz Suades, Albert Drew, David Degiacomi, Matteo T. Marklund, Erik G. Allison, Timothy M. Robinson, Carol V. Landreh, Michael Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title | Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title_full | Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title_fullStr | Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title_full_unstemmed | Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title_short | Electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
title_sort | electrospray ionization of native membrane proteins proceeds via a charge equilibration step |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8972943/ https://www.ncbi.nlm.nih.gov/pubmed/35424940 http://dx.doi.org/10.1039/d2ra01282k |
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