Comparative studies of nontoxic and toxic amyloids interacting with membrane models at the air-water interface
| Autor: | Bénédicte Coulary-Salin, Karine Berthelot, Bernard Desbat, Julie Géan, Christophe Cullin, Sophie Lecomte, Laurent Servant, Ha Phuong Ta |
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| Přispěvatelé: | Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Chimie et Biologie des Membranes et des Nanoobjets (CBMN), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Grellety, Marie-Lise |
| Rok vydání: | 2011 |
| Předmět: |
Amyloid
Mutant Phospholipid [SDV.BC]Life Sciences [q-bio]/Cellular Biology Antiparallel (biochemistry) chemistry.chemical_compound Microscopy Electron Transmission Monolayer Electrochemistry Humans General Materials Science [SDV.BC] Life Sciences [q-bio]/Cellular Biology Spectroscopy ComputingMilieux_MISCELLANEOUS Phospholipids Chemistry Air Spectrum Analysis Water Membranes Artificial Surfaces and Interfaces Condensed Matter Physics In vitro Crystallography Membrane Transmission electron microscopy Biophysics |
| Zdroj: | Langmuir Langmuir, American Chemical Society, 2011, 27 (8), pp.4797-4807 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | Many in vitro studies have pointed out the interaction between amyloids and membranes, and their potential involvement in amyloid toxicity. In a previous study, we generated a yeast toxic mutant (M8) of the harmless model amyloid protein HET-s((218-289)). In this study, we compared the self-assembling process of the nontoxic wild-type (WT) and toxic (M8) protein at the air-water interface and in interaction with various phospholipid monolayers (DOPE, DOPC, DOPI, DOPS and DOPG). We first demonstrate using ellipsometry measurements and polarization-modulated infrared reflection absorption spectroscopy (PMIRRAS) that the air-water interface promotes and modifies the assembly of WT since an amyloid-like film was instantaneously formed at the interface with an antiparallel β-sheet structuration instead of the parallel β-sheet commonly observed for amyloid fibers generated in solution. The toxic mutant (M8) behaves in a similar manner at the air-water interface or in bulk, with a fast self-assembling and an antiparallel β-sheet organization. The transmission electron microscopy (TEM) images established the fibrillous morphology of the protein films formed at the air-water interface. Second, we demonstrate for the first time that the main driving force between this particular fungus amyloid and membrane interaction is based on electrostatic interactions with negatively charged phospholipids (DOPG, DOPI, DOPS). Interestingly, the toxic mutant (M8) clearly induces perturbations of the negatively charged phospholipid monolayers, leading to a massive surface aggregation, whereas the nontoxic (WT) exhibits a slight effect on the membrane models. This study allows concluding that the toxicity of the M8 mutant could be due to its high propensity to interact with membranes. |
| Databáze: | OpenAIRE |
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