Skip to Main content Skip to Navigation
Theses

Formation de domaines de type "rafts" dans des vésicules unilamellaires et mécanismes physico-chimiques de l'extraction de domaines membranaires

Abstract : Model membranes represent a necessary tool to study biological membranes. Indeed, they have widely contributed to their description. In this work, we have been interesting in the study of the liquid-ordered/liquid-disordered (lo/ld) phase coexistence within LUV (Large Unilamellar Vesicle) membranes model. First, we have attempted to develop a methodology both allowing the detection of lo phase formation and the quantitative estimation of membrane fraction Φo occupied by lo phase in LUV of ternary composition: PC/SM/Chol (phosphatidylcholine / sphingomyeline / cholesterol), able to induce a phase coexistence. For this purpose, the properties of fluorescence self-quenching and selective partitioning between lipid phases of a unique fluorescent probe (C12NBD-PC) were used. The second part of our work has been dedicated to the study of the solubilization of LUVs showing lo/ld phase coexistence by Triton X-100 detergent. Our aim was to demonstrate the possibility to extract strictly lo phase membrane fraction. For this, structural transitions induced by Triton X-100 interactions with LUVs at 4°C were studied using a separation procedure by density gradient. We have attempted to evaluate detergent to lipids ratio permitting the isolation of resistant fractions corresponding to the lo domains existing in LUVs membrane before detergent addition.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00116250
Contributor : Virginie Coste <>
Submitted on : Friday, November 24, 2006 - 7:59:39 PM
Last modification on : Monday, December 14, 2020 - 9:55:42 AM
Long-term archiving on: : Tuesday, April 6, 2010 - 8:01:40 PM

Identifiers

  • HAL Id : tel-00116250, version 1

Citation

Virginie Coste. Formation de domaines de type "rafts" dans des vésicules unilamellaires et mécanismes physico-chimiques de l'extraction de domaines membranaires. Biophysique [physics.bio-ph]. Université Pierre et Marie Curie - Paris VI, 2006. Français. ⟨tel-00116250⟩

Share

Metrics

Record views

537

Files downloads

5922