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dc.contributor.author
Corvalán, Natalia Andrea
dc.contributor.author
Perillo, Maria Angelica
dc.date.available
2021-05-21T01:56:59Z
dc.date.issued
2020-02
dc.identifier.citation
Corvalán, Natalia Andrea; Perillo, Maria Angelica; Probing Thermotropic Phase Behavior of Dipalmitoylphosphatidylcholine Bilayers from Electrical and Topographic Data in a Horizontal Black Lipid Membrane Model; American Chemical Society; Langmuir; 36; 5; 2-2020; 1083-1093
dc.identifier.issn
0743-7463
dc.identifier.uri
http://hdl.handle.net/11336/132433
dc.description.abstract
Here, a homemade device allowed preparing horizontal lipid bilayer membranes (hBLMs) for recording electrical and topographical data simultaneously and in real-time, under temperature (T)-controlled conditions along a cooling process of dipalmitoylphosphatidylcholine (DPPC) bilayers. Electrical parameters (ionic current intensity, I, and transmembrane resistance, R = ΔV/I) plotted against T exhibited discontinuities at the main transition (TPβ′→Lα ) and pretransition (TLβ→Pβ′ ) temperatures of DPPC. The T-dependent sensitivity to ΔV-induced electrostriction was revealed by capacitance measurements. The patterns of I fluctuation described long-range correlations reflected by 1/f-type noise in the ripple phase (Pβ′) and Brownian-type fluctuations in the liquid-crystalline (Lα) phase at voltage intensities lower than a voltage threshold (ΔVth = ±160 mV), indicating that autocorrelations arise from an underlying structural connectivity that takes place within ordered phases. At |V| ≥ Vth, the fluctuation dynamics exhibited a 1/f behavior over the whole temperature range analyzed, suggesting that upon a certain intensity of external electrical perturbation, the membrane system evolves toward a voltage-induced percolated-pore state. At T > TPβ′→Lα , differential interference contrast micrographs showed droplet-like structures, probably containing solvent traces of the lipid solution, which were reverted upon cooling. However, droplets did not interfere with the thermotropic equilibrium of the bilayer phase. This suggested that the temperature-induced changes in the electrical properties of the bilayer, as well as in the complexity of the fluctuation patterns (emergency of long- and short-range correlations), were strongly associated with the characteristic thermotropic behavior of DPPC, without significant deviations induced by the presence of residual n-decane in the bilayer. Our hBLM model membrane proved useful for correlating thermotropic phase changes with electro-biophysical and topographical information.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
American Chemical Society
dc.rights
info:eu-repo/semantics/restrictedAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
horizontal black lipid membranes
dc.subject
DPPC
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thermotropic equilibrium
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membrane topography
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transmembrane ionic current
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membrane resistance
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membrane capacitance
dc.subject.classification
Biofísica
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Ciencias Biológicas
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
Probing Thermotropic Phase Behavior of Dipalmitoylphosphatidylcholine Bilayers from Electrical and Topographic Data in a Horizontal Black Lipid Membrane Model
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2021-05-11T18:10:59Z
dc.identifier.eissn
1520-5827
dc.journal.volume
36
dc.journal.number
5
dc.journal.pagination
1083-1093
dc.journal.pais
Estados Unidos
dc.description.fil
Fil: Corvalán, Natalia Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
dc.description.fil
Fil: Perillo, Maria Angelica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
dc.journal.title
Langmuir
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/acs.langmuir.9b02854
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1021/acs.langmuir.9b02854
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