Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study
- Autores
- Maté, Sabina María; Vázquez, Romina Florencia; Herlax, Vanesa Silvana; Daza Millone, María Antonieta; Fanani, María L.; Maggio, Bruno; Vela, María Elena; Bakás, Laura Susana
- Año de publicación
- 2014
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- α-Hemolysin (HlyA) is a protein toxin, a member of the pore-forming Repeat in Toxin (RTX) family, secreted by some pathogenic strands of Escherichia coli. The mechanism of action of this toxin seems to involve three stages that ultimately lead to cell lysis: binding, insertion, and oligomerization of the toxin within the membrane. Since the influence of phase segregation on HlyA binding and insertion in lipid membranes is not clearly understood, we explored at the meso- and nanoscale - both in situ and in real-time - the interaction of HlyA with lipid monolayers and bilayers. Our results demonstrate that HlyA could insert into monolayers of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/16:0SM/Cho) and DOPC/24:1SM/Cho. The time course for HlyA insertion was similar in both lipidic mixtures. HlyA insertion into DOPC/16:0SM/Cho monolayers, visualized by Brewster-angle microscopy (BAM), suggest an integration of the toxin into both the liquid-ordered and liquid-expanded phases. Atomic-force-microscopy imaging reported that phase boundaries favor the initial binding of the toxin, whereas after a longer time period the HlyA becomes localized into the liquid-disordered (Ld) phases of supported planar bilayers composed of DOPC/16:0SM/Cho. Our AFM images, however, showed that the HlyA interaction does not appear to match the general strategy described for other invasive proteins. We discuss these results in terms of the mechanism of action of HlyA.
Instituto de Investigaciones Bioquímicas de La Plata
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Facultad de Ciencias Exactas - Materia
-
Ciencias Exactas
Liquid-disordered phase
Liquid-ordered phase
Monolayer
Pore-forming toxin
Supported lipid bilayer - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/85271
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Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time studyMaté, Sabina MaríaVázquez, Romina FlorenciaHerlax, Vanesa SilvanaDaza Millone, María AntonietaFanani, María L.Maggio, BrunoVela, María ElenaBakás, Laura SusanaCiencias ExactasLiquid-disordered phaseLiquid-ordered phaseMonolayerPore-forming toxinSupported lipid bilayerα-Hemolysin (HlyA) is a protein toxin, a member of the pore-forming Repeat in Toxin (RTX) family, secreted by some pathogenic strands of <i>Escherichia coli</i>. The mechanism of action of this toxin seems to involve three stages that ultimately lead to cell lysis: binding, insertion, and oligomerization of the toxin within the membrane. Since the influence of phase segregation on HlyA binding and insertion in lipid membranes is not clearly understood, we explored at the meso- and nanoscale - both <i>in situ</i> and in <i>real-time</i> - the interaction of HlyA with lipid monolayers and bilayers. Our results demonstrate that HlyA could insert into monolayers of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/16:0SM/Cho) and DOPC/24:1SM/Cho. The time course for HlyA insertion was similar in both lipidic mixtures. HlyA insertion into DOPC/16:0SM/Cho monolayers, visualized by Brewster-angle microscopy (BAM), suggest an integration of the toxin into both the liquid-ordered and liquid-expanded phases. Atomic-force-microscopy imaging reported that phase boundaries favor the initial binding of the toxin, whereas after a longer time period the HlyA becomes localized into the liquid-disordered (<i>Ld</i>) phases of supported planar bilayers composed of DOPC/16:0SM/Cho. Our AFM images, however, showed that the HlyA interaction does not appear to match the general strategy described for other invasive proteins. We discuss these results in terms of the mechanism of action of HlyA.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exactas2014info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1832-1841http://sedici.unlp.edu.ar/handle/10915/85271enginfo:eu-repo/semantics/altIdentifier/issn/0005-2736info:eu-repo/semantics/altIdentifier/doi/10.1016/j.bbamem.2014.02.022info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:16:24Zoai:sedici.unlp.edu.ar:10915/85271Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:25.171SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
title |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
spellingShingle |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study Maté, Sabina María Ciencias Exactas Liquid-disordered phase Liquid-ordered phase Monolayer Pore-forming toxin Supported lipid bilayer |
title_short |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
title_full |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
title_fullStr |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
title_full_unstemmed |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
title_sort |
Boundary region between coexisting lipid phases as initial binding sites for Escherichia coli alpha-hemolysin: A real-time study |
dc.creator.none.fl_str_mv |
Maté, Sabina María Vázquez, Romina Florencia Herlax, Vanesa Silvana Daza Millone, María Antonieta Fanani, María L. Maggio, Bruno Vela, María Elena Bakás, Laura Susana |
author |
Maté, Sabina María |
author_facet |
Maté, Sabina María Vázquez, Romina Florencia Herlax, Vanesa Silvana Daza Millone, María Antonieta Fanani, María L. Maggio, Bruno Vela, María Elena Bakás, Laura Susana |
author_role |
author |
author2 |
Vázquez, Romina Florencia Herlax, Vanesa Silvana Daza Millone, María Antonieta Fanani, María L. Maggio, Bruno Vela, María Elena Bakás, Laura Susana |
author2_role |
author author author author author author author |
dc.subject.none.fl_str_mv |
Ciencias Exactas Liquid-disordered phase Liquid-ordered phase Monolayer Pore-forming toxin Supported lipid bilayer |
topic |
Ciencias Exactas Liquid-disordered phase Liquid-ordered phase Monolayer Pore-forming toxin Supported lipid bilayer |
dc.description.none.fl_txt_mv |
α-Hemolysin (HlyA) is a protein toxin, a member of the pore-forming Repeat in Toxin (RTX) family, secreted by some pathogenic strands of <i>Escherichia coli</i>. The mechanism of action of this toxin seems to involve three stages that ultimately lead to cell lysis: binding, insertion, and oligomerization of the toxin within the membrane. Since the influence of phase segregation on HlyA binding and insertion in lipid membranes is not clearly understood, we explored at the meso- and nanoscale - both <i>in situ</i> and in <i>real-time</i> - the interaction of HlyA with lipid monolayers and bilayers. Our results demonstrate that HlyA could insert into monolayers of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/16:0SM/Cho) and DOPC/24:1SM/Cho. The time course for HlyA insertion was similar in both lipidic mixtures. HlyA insertion into DOPC/16:0SM/Cho monolayers, visualized by Brewster-angle microscopy (BAM), suggest an integration of the toxin into both the liquid-ordered and liquid-expanded phases. Atomic-force-microscopy imaging reported that phase boundaries favor the initial binding of the toxin, whereas after a longer time period the HlyA becomes localized into the liquid-disordered (<i>Ld</i>) phases of supported planar bilayers composed of DOPC/16:0SM/Cho. Our AFM images, however, showed that the HlyA interaction does not appear to match the general strategy described for other invasive proteins. We discuss these results in terms of the mechanism of action of HlyA. Instituto de Investigaciones Bioquímicas de La Plata Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas Facultad de Ciencias Exactas |
description |
α-Hemolysin (HlyA) is a protein toxin, a member of the pore-forming Repeat in Toxin (RTX) family, secreted by some pathogenic strands of <i>Escherichia coli</i>. The mechanism of action of this toxin seems to involve three stages that ultimately lead to cell lysis: binding, insertion, and oligomerization of the toxin within the membrane. Since the influence of phase segregation on HlyA binding and insertion in lipid membranes is not clearly understood, we explored at the meso- and nanoscale - both <i>in situ</i> and in <i>real-time</i> - the interaction of HlyA with lipid monolayers and bilayers. Our results demonstrate that HlyA could insert into monolayers of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/16:0SM/Cho) and DOPC/24:1SM/Cho. The time course for HlyA insertion was similar in both lipidic mixtures. HlyA insertion into DOPC/16:0SM/Cho monolayers, visualized by Brewster-angle microscopy (BAM), suggest an integration of the toxin into both the liquid-ordered and liquid-expanded phases. Atomic-force-microscopy imaging reported that phase boundaries favor the initial binding of the toxin, whereas after a longer time period the HlyA becomes localized into the liquid-disordered (<i>Ld</i>) phases of supported planar bilayers composed of DOPC/16:0SM/Cho. Our AFM images, however, showed that the HlyA interaction does not appear to match the general strategy described for other invasive proteins. We discuss these results in terms of the mechanism of action of HlyA. |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
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article |
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http://sedici.unlp.edu.ar/handle/10915/85271 |
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dc.language.none.fl_str_mv |
eng |
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eng |
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info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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