Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process

Fatty acid transfer from intestinal fatty acid-binding protein (IFABP) to phospholipid membranes occurs during protein-membrane collisions. Electrostatic interactions involving the α-helical "portal" region of the protein have been shown to be of great importance. In the present study, the...

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Autores principales: Falomir Lockhart, Lisandro J., Laborde, Lisandro, Kahn, Peter C., Storch, Judith, Córsico, Betina
Formato: Articulo
Lenguaje:Inglés
Publicado: 2006
Materias:
Bioquímica
Intestinal fatty acid-binding protein
Electrostatic interactions
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83283
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83283
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Bioquímica
Intestinal fatty acid-binding protein
Electrostatic interactions
spellingShingle Bioquímica
Intestinal fatty acid-binding protein
Electrostatic interactions
Falomir Lockhart, Lisandro J.
Laborde, Lisandro
Kahn, Peter C.
Storch, Judith
Córsico, Betina
Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
topic_facet Bioquímica
Intestinal fatty acid-binding protein
Electrostatic interactions
description Fatty acid transfer from intestinal fatty acid-binding protein (IFABP) to phospholipid membranes occurs during protein-membrane collisions. Electrostatic interactions involving the α-helical "portal" region of the protein have been shown to be of great importance. In the present study, the role of specific lysine residues in the α-helical region of IFABP was directly examined. A series of point mutants in rat IFABP was engineered in which the lysine positive charges in this domain were eliminated or reversed. Using a fluorescence resonance energy transfer assay, we analyzed the rates and mechanism of fatty acid transfer from wild type and mutant proteins to acceptor membranes. Most of the α-helical domain mutants showed slower absolute fatty acid transfer rates to zwitterionic membranes, with substitution of one of the lysines of the α2 helix, Lys27, resulting in a particularly dramatic decrease in the fatty acid transfer rate. Sensitivity to negatively charged phospholipid membranes was also reduced, with charge reversal mutants in the α2 helix the most affected. The results support the hypothesis that the portal region undergoes a conformational change during protein-membrane interaction, which leads to release of the bound fatty acid to the membrane and that the α2 segment is of particular importance in the establishment of charge-charge interactions between IFABP and membranes. Cross-linking experiments with a phospholipid-photoactivable reagent underscored the importance of charge-charge interactions, showing that the physical interaction between wild-type intestinal fatty acid-binding protein and phospholipid membranes is enhanced by electrostatic interactions. Protein-membrane interactions were also found to be enhanced by the presence of ligand, suggesting different collisional complex structures for holo- and apo-IFABP.
format Articulo
Articulo
author Falomir Lockhart, Lisandro J.
Laborde, Lisandro
Kahn, Peter C.
Storch, Judith
Córsico, Betina
author_facet Falomir Lockhart, Lisandro J.
Laborde, Lisandro
Kahn, Peter C.
Storch, Judith
Córsico, Betina
author_sort Falomir Lockhart, Lisandro J.
title Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
title_short Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
title_full Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
title_fullStr Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
title_full_unstemmed Protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: Support for a multistep process
title_sort protein-membrane interaction and fatty acid transfer from intestinal fatty acid-binding protein to membranes: support for a multistep process
publishDate 2006
url http://sedici.unlp.edu.ar/handle/10915/83283
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