Artículo
Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles
Fecha de publicación:
12/2009
Editorial:
Springer
Revista:
European Biophysics Journal With Biophysics Letters
ISSN:
0175-7571
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
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 outcomes 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 can not identify this source of heterogeneity, a mathematical modeling approach was developed based on phenomenological equations of water transport. In the three comparative models here presented, 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 here presented mathematical approach allows to identify the source of heterogeneity; being this information of particular interest, especially when studying gating mechanisms triggered in water channel activity.
Palabras clave:
aquaporins
,
water permeability
,
osmosis
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Identificadores
Colecciones
Articulos(IFLYSIB)
Articulos de INST.FISICA DE LIQUIDOS Y SIST.BIOLOGICOS (I)
Articulos de INST.FISICA DE LIQUIDOS Y SIST.BIOLOGICOS (I)
Articulos(OCA CIUDAD UNIVERSITARIA)
Articulos de OFICINA DE COORDINACION ADMINISTRATIVA CIUDAD UNIVERSITARIA
Articulos de OFICINA DE COORDINACION ADMINISTRATIVA CIUDAD UNIVERSITARIA
Citación
Alleva, Karina Edith; Chara, Osvaldo; Sutka, Moira Romina; Amodeo, Gabriela; Analysis of the source of heterogeneity in the osmotic response of plant membrane vesicles; Springer; European Biophysics Journal With Biophysics Letters; 38; 2; 12-2009; 175-184
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