Dynamics of the membrane lipid phase
| Autor: | A. Zachowski, S. Cribier, G. Morrot |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Magnetic Resonance Spectroscopy
Chemical Phenomena Rotation Stereochemistry Membrane Fluidity Membrane lipids Clinical Biochemistry Lipid Bilayers Biological Transport Active Diffusion Membrane Lipids Motion Membrane fluidity Lipid bilayer phase behavior Semipermeable membrane Lipid bilayer Phospholipids Chemistry Chemistry Physical Peripheral membrane protein Membrane Proteins Biological membrane Cell Biology Biophysics lipids (amino acids peptides and proteins) Elasticity of cell membranes |
| Zdroj: | Prostaglandins, leukotrienes, and essential fatty acids. 48(1) |
| ISSN: | 0952-3278 |
| Popis: | The lipid bilayer of a membrane is sometimes seen as an inert hydrophobic phase allowing the ‘solubility’ of transmembrane proteins and acting as a barrier between two compartments. However, the bilayer is, in fact, a highly organized system subjected to many movements leading to a dynamically equilibrated structure. A lipid within a membrane experiences intramolecular motions (movement of some segments of the molecule) and moves or diffuses in and across each monolayer. In plasma membranes, transverse diffusion is either passive (cholinecontaining phospholipids, fatty acids …) or active via a carrier protein (amino-phospholipids). The known asymmetric transverse distribution of phospholipids between the two plasma membrane leaflets is a stationary state resulting from all these motions, especially the active transport. Nevertheless, recent studies have shown that it is also possible to obtain an uneven distribution of some lipids (e.g. fatty acid, phosphatidic acid) across a membrane via a pH gradient. Lateral diffusion within a monolayer depends on the composition of the monolayer and not on the nature of the diffusing lipid. The phospholipid asymmetry, based on the polar head groups, exists also for the corresponding fatty acids, as the nature of the acyl chains differs according to the head group. A consequence is that the cytoplasmic leaflet of plasma membranes has a different ‘fluidity’ from that of the outer leaflet. |
| Databáze: | OpenAIRE |
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