Visualizing association of N-ras in lipid microdomains: influence of domain structure and interfacial adsorption
| Autor: | Jose M. Palomo, Martin Kahms, Enrico Gratton, Roland Winter, Stefanie Schlummer, Susana A. Sanchez, Maria Lumbierres-Burgues, Jürgen Kuhlmann, Chiara Nicolini, Herbert Waldmann, Jörg Baranski |
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| Rok vydání: | 2006 |
| Předmět: |
Boron Compounds
Models Molecular Stereochemistry Phospholipid Microscopy Atomic Force Biochemistry Catalysis chemistry.chemical_compound Membrane Lipids Colloid and Surface Chemistry Membrane Microdomains Lipid bilayer POPC Fluorescent Dyes Vesicle Lipid microdomain Biological membrane General Chemistry Raft Sphingomyelins Cholesterol chemistry Microscopy Fluorescence Biophysics Phosphatidylcholines ras Proteins lipids (amino acids peptides and proteins) Sphingomyelin |
| Zdroj: | Nicolini, C; Baranski, J; Schlummer, S; Palomo, J; Lumbierres-Burgues, M; Kahms, M; et al.(2006). Visualizing association of N-Ras in lipid microdomains: Influence of domain structure and interfacial adsorption. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 128(1), 192-201. doi: 10.1021/ja055779x. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/9f54k8kz |
| ISSN: | 0002-7863 |
| DOI: | 10.1021/ja055779x. |
| Popis: | In this study, two-photon fluorescence microscopy on giant unilamellar vesicles and tapping-mode atomic force microscopy (AFM) are applied to follow the insertion of a fluorescently (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, BODIPY) labeled and completely lipidated (hexadecylated and farnesylated) N-Ras protein into heterogeneous lipid bilayer systems. The bilayers consist of the canonical raft mixture 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), sphingomyelin, and cholesterol, which-depending on the concentration of the constituents-separates into liquid-disordered (l(d)), liquid-ordered (l(o)), and solid-ordered (s(o)) phases. The results provide direct evidence that partitioning of N-Ras occurs preferentially into liquid-disordered lipid domains, which is also reflected in a faster kinetics of incorporation into the fluid lipid bilayers. The phase sequence of preferential binding of N-Ras to mixed-domain lipid vesicles is l(d) > l(o) >> s(o). Intriguingly, we detect, using the better spatial resolution of AFM, also a large proportion of the lipidated protein located at the l(d)/l(o) phase boundary, thus leading to a favorable decrease in line tension that is associated with the rim of the demixed phases. Such an interfacial adsorption effect may serve as an alternative vehicle for association processes of signaling proteins in membranes. |
| Databáze: | OpenAIRE |
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