| dc.creator |
Contreras, F. Xabier |
|
| dc.creator |
Basañez, Gorka |
|
| dc.creator |
Alonso, Alicia |
|
| dc.creator |
Herrmann, Andreas |
|
| dc.creator |
Goñi, Félix M. |
|
| dc.date |
2008-04-11T09:36:09Z |
|
| dc.date |
2008-04-11T09:36:09Z |
|
| dc.date |
2005-01 |
|
| dc.date.accessioned |
2017-01-31T01:01:59Z |
|
| dc.date.available |
2017-01-31T01:01:59Z |
|
| dc.identifier |
Biophys J. 2005 January; 88(1): 348–359 |
|
| dc.identifier |
1542-0086 |
|
| dc.identifier |
http://hdl.handle.net/10261/3540 |
|
| dc.identifier |
10.1529/biophysj.104.050690 |
|
| dc.identifier.uri |
http://dspace.mediu.edu.my:8181/xmlui/handle/10261/3540 |
|
| dc.description |
Copyright © by Biophysical Society. Final full-text version of the paper available at: http://www.biophysj.org/cgi/content/abstract/88/1/348 |
|
| dc.description |
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. |
|
| dc.description |
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. |
|
| dc.description |
Peer reviewed |
|
| dc.format |
176238 bytes |
|
| dc.format |
application/pdf |
|
| dc.language |
eng |
|
| dc.publisher |
Biophysical Society |
|
| dc.rights |
openAccess |
|
| dc.title |
Asymmetric Addition of Ceramides but not Dihydroceramides Promotes Transbilayer (Flip-Flop) Lipid Motion in Membranes |
|
| dc.type |
Artículo |
|