Beyond Saffman-Delbruck approximation: A new regime for 2D diffusion of α-hemolysin complexes in supported lipid bilayer
| Autor: | Natalie Ferté, Joe Sarkis, Frédéric Harb, Bernard Tinland |
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| Rok vydání: | 2012 |
| Předmět: |
Range (particle radiation)
Chemistry Bilayer Diffusion Bacterial Toxins Lipid Bilayers Temperature Biophysics Hemolysin Nanotechnology Surfaces and Interfaces General Chemistry Fluorescence Photobleaching Hemolysin Proteins Membrane dynamics General Materials Science Dimyristoylphosphatidylcholine Lipid bilayer Biotechnology |
| Zdroj: | The European Physical Journal E. 35 |
| ISSN: | 1292-895X 1292-8941 |
| DOI: | 10.1140/epje/i2012-12118-6 |
| Popis: | Cell mechanisms are actively modulated by membrane dynamics. We studied the dynamics of a first-stage biomimetic system by Fluorescence Recovery After Patterned Photobleaching. Using this simple biomimetic system, constituted by α -hemolysin from Staphylococcus aureus inserted as single heptameric pore or complexes of pores in a glass-supported DMPC bilayer, we observed true diffusion behavior, with no immobile fraction. We find two situations: i) when incubation is shorter than 15 hours, the protein inserts as a heptameric pore and diffuses roughly three times more slowly than its host lipid bilayer; ii) incubation longer than 15 hours leads to the formation of larger complexes which diffuse more slowly. Our results indicate that, while the Saffman-Delbruck model adequately describes the diffusion coefficient D for small radii, D of the objects decreases as 1/R(2) for the size range explored in this study. Additionally, in the presence of inserted proteins, the gel-to-fluid transition of the supported bilayer as well as a temperature shift in the gel-to-fluid transition are observed. |
| Databáze: | OpenAIRE |
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