Lipid rafts reconstituted in model membranes.

C. DIETRICH; LUIS A. BAGATOLLI; Z.N. VOLOVYK; N. THOMPSON; M. LEVI; K. JACOBSON; E.GRATTON

BIOPHYSICAL JOURNAL

CELL PRESS

Lugar: United States; Año: 2001 vol. 80 p. 1417 - 1417

0006-3495

ne key tenet of the raft hypothesis is that the formation of glycosphingolipid- and cholesterol-rich lipid domains can be driven solely by characteristic lipid-lipid interactions, suggesting that rafts ought to form in model membranes composed of appropriate lipids. In fact, domains with raft-like properties were found to coexist with fluid lipid regions in both planar supported lipid layers and in giant unilamellar vesicles (GUVs) formed from 1) equimolar mixtures of phospholipid-cholesterol-sphingomyelin or 2) natural lipids extracted from brush border membranes that are rich in sphingomyelin and cholesterol. Employing headgroup-labeled fluorescent phospholipid analogs in planar supported lipid layers, domains typically several microns in diameter were observed by fluorescence microscopy at room temperature (24 degrees C) whereas non-raft mixtures (PC-cholesterol) appeared homogeneous. Both raft and non-raft domains were fluid-like, although diffusion was slower in raft domains, and