Asymmetric Addition of Ceramides but not Dihydroceramides Promotes Transbilayer (Flip-Flop) Lipid Motion in Membranes
| Autor: | Félix M. Goñi, Andreas Herrmann, Gorka Basañez, Alicia Alonso, F.-Xabier Contreras |
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| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
Ceramide
Time Factors Lipid Bilayers Biophysics Phospholipid Phosphatidylserines Sphingomyelin phosphodiesterase Ceramides GeneralLiterature_MISCELLANEOUS Diffusion Diglycerides Cell membrane chemistry.chemical_compound Bacillus cereus Phosphatidylcholine Fluorescence Resonance Energy Transfer medicine Humans Lipid bilayer GeneralLiterature_REFERENCE(e.g. dictionaries encyclopedias glossaries) Phosphatidylethanolamine Membranes Models Statistical Pyrenes Chemistry Cell Membrane Erythrocyte Membrane Lysophosphatidylcholines Lipids Cholesterol Sphingomyelin Phosphodiesterase medicine.anatomical_structure Biochemistry Type C Phospholipases Liposomes Phosphatidylcholines ComputingMethodologies_DOCUMENTANDTEXTPROCESSING lipids (amino acids peptides and proteins) Sphingomyelin |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Copyright © by Biophysical Society. Final full-text version of the paper available at: http://www.biophysj.org/cgi/content/abstract/88/1/348 Transbilayer lipid motion in membranes may be important in certain physiological events, such as ceramide signaling. In this study, the transbilayer redistribution of lipids induced either by ceramide addition or by enzymatic ceramide generation at one side of the membrane has been monitored using pyrene-labeled phospholipid analogs. When added in organic solution to preformed liposomes, egg ceramide induced transbilayer lipid motion in a dose-dependent way. Short-chain (C6 and C2) ceramides were less active than egg ceramide, whereas dihydroceramides or dioleoylglycerol were virtually inactive in promoting flip-flop. The same results (either positive or negative) were obtained when ceramides, dihydroceramides, or diacylglycerols were generated in situ through the action of a sphingomyelinase or of a phospholipase C. The phenomenon was dependent on the bilayer lipid composition, being faster in the presence of lipids that promote inverted phase formation, e.g., phosphatidylethanolamine and cholesterol; and, conversely, slower in the presence of lysophosphatidylcholine, which inhibits inverted phase formation. Transbilayer motion was almost undetectable in bilayers composed of pure phosphatidylcholine or pure sphingomyelin. The use of pyrene-phosphatidylserine allowed detection of flip-flop movement induced by egg ceramide in human red blood cell membranes at a rate comparable to that observed in model membranes. The data suggest that when one membrane leaflet becomes enriched in ceramides, they diffuse toward the other leaflet. This is counterbalanced by lipid movement in the opposite direction, so that net mass transfer between monolayers is avoided. These observations may be relevant to the physiological mechanism of transmembrane signaling via ceramides. This work was supported in part by grants (BMC2002-00784/BMC2001- 0791) from Ministerio de Ciencia y Tecnología (Spain) and grant (042.310- 13552/2001) from the University of the Basque Country. F.-X.C. was a predoctoral Fellow of the Basque Government. |
| Databáze: | OpenAIRE |
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