Water dynamics in glycosphingolipid aggregates studied by LAURDAN fluorescence.

LUIS A. BAGATOLLI; E. GRATTON; GERARDO D. FIDELIO

BIOPHYSICAL JOURNAL

CELL PRESS

Lugar: United States; Año: 1998 vol. 75 p. 331 - 331

0006-3495

e have characterized the fluorescence properties of 6-dodecanoyl-2-dimethylamine-naphthalene (LAURDAN) in pure interfaces formed by sphingomyelin and 10 chemically related glycosphingolipids (GSLs).1 The GSLs contain neutral and anionic carbohydrate residues in their oligosaccharide chain. These systems were studied at temperatures below, at, or above the main phase transition temperature of the pure lipid aggregates. The extent of solvent dipolar relaxation around the excited fluorescence probe in the GSLs series increases with the magnitude of the glycosphingolipid polar headgroup below the transition temperature. This conclusion is based on LAURDAN's excitation generalized polarization (GPex) and fluorescence lifetime values found in the different interfaces. A linear dependence between the LAURDAN GPex and the intermolecular spacing among the lipid molecules was found for both neutral and anionic lipids in the GSLs series. This relationship was also followed by phospholipids. We c