Cargando…

Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration

Polymer-encapsulated nanodiscs enable membrane proteins to be investigated within a native-like lipid-bilayer environment. Unlike other bilayer-based membrane mimetics, these nanodiscs are equilibrium structures that permit lipid exchange on experimentally relevant timescales. Therefore, examining t...

Descripción completa

Detalles Bibliográficos
Autores principales: Eggenreich, Loretta, Vargas, Carolyn, Kolar, Cenek, Keller, Sandro
Formato: Online Artículo Texto
Lenguaje:English
Publicado: De Gruyter 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10263143/
https://www.ncbi.nlm.nih.gov/pubmed/36921292
http://dx.doi.org/10.1515/hsz-2022-0319
_version_ 1785058184328642560
author Eggenreich, Loretta
Vargas, Carolyn
Kolar, Cenek
Keller, Sandro
author_facet Eggenreich, Loretta
Vargas, Carolyn
Kolar, Cenek
Keller, Sandro
author_sort Eggenreich, Loretta
collection PubMed
description Polymer-encapsulated nanodiscs enable membrane proteins to be investigated within a native-like lipid-bilayer environment. Unlike other bilayer-based membrane mimetics, these nanodiscs are equilibrium structures that permit lipid exchange on experimentally relevant timescales. Therefore, examining the kinetics and mechanisms of lipid exchange is of great interest. Since the high charge densities of existing anionic polymers can interfere with protein–protein and protein–lipid interactions as well as charge-sensitive analysis techniques, electroneutral nanodisc-forming polymers have been recently introduced. However, it has remained unclear how the electroneutrality of these polymers affects the lipid-exchange behavior of the nanodiscs. Here, we use time-resolved Förster resonance energy transfer to study the kinetics and the mechanisms of lipid exchange among nanodiscs formed by the electroneutral polymer Sulfo-DIBMA. We also examine the role of coulombic repulsion and specific counterion association in lipid exchange. Our results show that Sulfo-DIBMA nanodiscs exchange lipids on a similar timescale as DIBMA nanodiscs. In contrast with nanodiscs made from polyanionic DIBMA, however, the presence of mono- and divalent cations does not influence lipid exchange among Sulfo-DIBMA nanodiscs, as expected from their electroneutrality. The robustness of Sulfo-DIBMA nanodiscs against varying ion concentrations opens new possibilities for investigating charge-sensitive processes involving membrane proteins.
format Online
Article
Text
id pubmed-10263143
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher De Gruyter
record_format MEDLINE/PubMed
spelling pubmed-102631432023-06-15 Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration Eggenreich, Loretta Vargas, Carolyn Kolar, Cenek Keller, Sandro Biol Chem Article Polymer-encapsulated nanodiscs enable membrane proteins to be investigated within a native-like lipid-bilayer environment. Unlike other bilayer-based membrane mimetics, these nanodiscs are equilibrium structures that permit lipid exchange on experimentally relevant timescales. Therefore, examining the kinetics and mechanisms of lipid exchange is of great interest. Since the high charge densities of existing anionic polymers can interfere with protein–protein and protein–lipid interactions as well as charge-sensitive analysis techniques, electroneutral nanodisc-forming polymers have been recently introduced. However, it has remained unclear how the electroneutrality of these polymers affects the lipid-exchange behavior of the nanodiscs. Here, we use time-resolved Förster resonance energy transfer to study the kinetics and the mechanisms of lipid exchange among nanodiscs formed by the electroneutral polymer Sulfo-DIBMA. We also examine the role of coulombic repulsion and specific counterion association in lipid exchange. Our results show that Sulfo-DIBMA nanodiscs exchange lipids on a similar timescale as DIBMA nanodiscs. In contrast with nanodiscs made from polyanionic DIBMA, however, the presence of mono- and divalent cations does not influence lipid exchange among Sulfo-DIBMA nanodiscs, as expected from their electroneutrality. The robustness of Sulfo-DIBMA nanodiscs against varying ion concentrations opens new possibilities for investigating charge-sensitive processes involving membrane proteins. De Gruyter 2023-06-27 2023-03-17 /pmc/articles/PMC10263143/ /pubmed/36921292 http://dx.doi.org/10.1515/hsz-2022-0319 Text en © 2023 the author(s), published by De Gruyter, Berlin/Boston https://creativecommons.org/licenses/by/4.0/This work is licensed under the Creative Commons Attribution 4.0 International License.
spellingShingle Article
Eggenreich, Loretta
Vargas, Carolyn
Kolar, Cenek
Keller, Sandro
Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title_full Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title_fullStr Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title_full_unstemmed Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title_short Lipid exchange among electroneutral Sulfo-DIBMA nanodiscs is independent of ion concentration
title_sort lipid exchange among electroneutral sulfo-dibma nanodiscs is independent of ion concentration
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10263143/
https://www.ncbi.nlm.nih.gov/pubmed/36921292
http://dx.doi.org/10.1515/hsz-2022-0319
work_keys_str_mv AT eggenreichloretta lipidexchangeamongelectroneutralsulfodibmananodiscsisindependentofionconcentration
AT vargascarolyn lipidexchangeamongelectroneutralsulfodibmananodiscsisindependentofionconcentration
AT kolarcenek lipidexchangeamongelectroneutralsulfodibmananodiscsisindependentofionconcentration
AT kellersandro lipidexchangeamongelectroneutralsulfodibmananodiscsisindependentofionconcentration