Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles

Plasma membrane vesicles have been widely employed to understand the biophysics of water movements, especially when active aquaporins are present. In general, water permeability coefficients in these preparations outcome from the analysis of the osmotic response of the vesicles by means of light sca...

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Authors: Alleva, Karina, Chara, Osvaldo, Sutka, Moira, Amodeo, Gabriela
Format: article
Status:Published version
Publication Date:2008
Country:Argentina
Institution:Universidad Nacional de La Plata
Repository:SEDICI (UNLP)
Language:English
OAI Identifier:oai:sedici.unlp.edu.ar:10915/145882
Online Access:http://sedici.unlp.edu.ar/handle/10915/145882
Access Level:Open access
Keyword:Ciencias Exactas
Biología
Aquaporins
Stopped flow
Osmotic permeability
Mathematical modeling
Simulations
Water transport
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spelling Analysis of the source of heterogeneity in the osmotic response of plant membrane vesiclesAlleva, KarinaChara, OsvaldoSutka, MoiraAmodeo, GabrielaCiencias ExactasBiologíaAquaporinsStopped flowOsmotic permeabilityMathematical modelingSimulationsWater transportPlasma membrane vesicles have been widely employed to understand the biophysics of water movements, especially when active aquaporins are present. In general, water permeability coefficients in these preparations outcome from the analysis of the osmotic response of the vesicles by means of light scattering. As from now, this is possible by following a theoretical approach that assumes that scattered light follows a single exponential function and that this behavior is the consequence of vesicle volume changes due to an osmotic challenge. However, some experimental data do not necessarily fit to single exponentials but to double ones. It is argued that the observed double exponential behavior has two possible causes: different vesicle population in terms of permeability or in terms of size distribution. As classical models cannot identify this source of heterogeneity, a mathematical modeling approach was developed based on phenomenological equations of water transport. In the three comparative models presented here, it was assumed that water moves according to an osmotic mechanism across the vesicles, and there is no solute movement across them. Interestingly, when tested in a well described plasma membrane vesicle preparation, the application of these models indicates that the source of heterogeneity in the osmotic response is vesicles having different permeability, clearly discarding the variable size effect. In conclusion, the mathematical approach presented here allows to identify the source of heterogeneity; this information being of particular interest, especially when studying gating mechanisms triggered in water channel activity.Instituto de Física de Líquidos y Sistemas Biológicos2008-09-04info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf175-184http://sedici.unlp.edu.ar/handle/10915/145882enginfo:eu-repo/semantics/altIdentifier/issn/1432-1017info:eu-repo/semantics/altIdentifier/issn/0175-7571info:eu-repo/semantics/altIdentifier/doi/10.1007/s00249-008-0365-1info:eu-repo/semantics/altIdentifier/pmid/18769911info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2024-05-08T13:10:41Zoai:sedici.unlp.edu.ar:10915/145882Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292024-05-08 13:10:41.737SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
title Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
spellingShingle Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
Alleva, Karina
Ciencias Exactas
Biología
Aquaporins
Stopped flow
Osmotic permeability
Mathematical modeling
Simulations
Water transport
title_short Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
title_full Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
title_fullStr Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
title_full_unstemmed Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
title_sort Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
dc.creator.none.fl_str_mv Alleva, Karina
Chara, Osvaldo
Sutka, Moira
Amodeo, Gabriela
author Alleva, Karina
author_facet Alleva, Karina
Chara, Osvaldo
Sutka, Moira
Amodeo, Gabriela
author_role author
author2 Chara, Osvaldo
Sutka, Moira
Amodeo, Gabriela
author2_role author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Biología
Aquaporins
Stopped flow
Osmotic permeability
Mathematical modeling
Simulations
Water transport
topic Ciencias Exactas
Biología
Aquaporins
Stopped flow
Osmotic permeability
Mathematical modeling
Simulations
Water transport
description Plasma membrane vesicles have been widely employed to understand the biophysics of water movements, especially when active aquaporins are present. In general, water permeability coefficients in these preparations outcome from the analysis of the osmotic response of the vesicles by means of light scattering. As from now, this is possible by following a theoretical approach that assumes that scattered light follows a single exponential function and that this behavior is the consequence of vesicle volume changes due to an osmotic challenge. However, some experimental data do not necessarily fit to single exponentials but to double ones. It is argued that the observed double exponential behavior has two possible causes: different vesicle population in terms of permeability or in terms of size distribution. As classical models cannot identify this source of heterogeneity, a mathematical modeling approach was developed based on phenomenological equations of water transport. In the three comparative models presented here, it was assumed that water moves according to an osmotic mechanism across the vesicles, and there is no solute movement across them. Interestingly, when tested in a well described plasma membrane vesicle preparation, the application of these models indicates that the source of heterogeneity in the osmotic response is vesicles having different permeability, clearly discarding the variable size effect. In conclusion, the mathematical approach presented here allows to identify the source of heterogeneity; this information being of particular interest, especially when studying gating mechanisms triggered in water channel activity.
publishDate 2008
dc.date.none.fl_str_mv 2008-09-04
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/145882
url http://sedici.unlp.edu.ar/handle/10915/145882
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1432-1017
info:eu-repo/semantics/altIdentifier/issn/0175-7571
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00249-008-0365-1
info:eu-repo/semantics/altIdentifier/pmid/18769911
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
175-184
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
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instname_str Universidad Nacional de La Plata
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collection SEDICI (UNLP)
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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