Kinetics of lipid-membrane binding and conformational change of L-BABP

We designed an experimental approach to differentiate the kinetics of protein binding to a lipid membrane from the kinetics of the associated conformational change in the protein. We measured the fluorescence intensity of the single Trp6 in chicken liver bile acid-binding protein (L-BABP) as a funct...

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Detalles Bibliográficos
Autores: Galassi, Vanesa Viviana, Nolan, María Verónica, Villarreal, Marcos Ariel, Perducca, Massimiliano, Monaco, Hugo L., Montich, Guillermo Gabriel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2009
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/53929
Acceso en línea:http://hdl.handle.net/11336/53929
Access Level:acceso abierto
Palabra clave:Fluorescence
Kinetics
L-Babp
Protein Binding to Lipid Membrane
Protein Unfolding
Stopped-Flow
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:We designed an experimental approach to differentiate the kinetics of protein binding to a lipid membrane from the kinetics of the associated conformational change in the protein. We measured the fluorescence intensity of the single Trp6 in chicken liver bile acid-binding protein (L-BABP) as a function of time after mixing the protein with lipid membranes. We mixed the protein with pure lipid membranes, with lipid membranes in the presence of a soluble quencher, and with lipid membranes containing a fluorescence quencher attached to the lipid polar head group. We fitted simultaneously the experimental curves to a three-state kinetic model. We conclude that in a first step, the binding of L-BABP to the interfacial region of the anionic lipid polar head groups occurred simultaneously with a conformational change to the partly unfolded state. In a second slower step, Trp6 buried within the polar head group region, releasing contacts with the aqueous phase. © 2009 Elsevier Inc. All rights reserved.