Shape transitions and lattice structuring of ceramide-enriched domains generated by sphingomyelinase activity in lipid monolayers

STEFFEN HÄRTER, MARÍA L. FANANI, AND BRUNO MAGGIO

BIOPHYSICAL JOURNAL

Año: 2005 vol. 88 p. 287 - 287

0006-3495

nbsp; Sphingomyelinases (SMases) hydrolyze the membrane constituent sphingomyelin (SM) to phosphocholine and ceramide (Cer). Growing evidence supports that SMase-induced SM/Cer conversion leads to the formation of lateral Cerenriched domains which drive structural reorganization in lipid membranes.Wepreviously provided visual evidence in real-time for the formation of Cer-enriched domains in SM monolayers through the action of the neutral Bacillus cereus SMase. In this work, we disclose a succession of discrete morphologic transitions and lateral organization of Cer-enriched domains that underlay the SMase-generated surface topography. We further reveal how these structural parameters couple to the generation of twodimensional electrostatic .elds, based upon the speci.c orientation of the lipid dipole moments in the Cer-enriched domains. Advanced image process