Thermotropic behavior and lateral distribution of very long chain sphingolipids.

YJ BJÖRKQVIST ; J. BREWER; LUIS A. BAGATOLLI; P. SLOTTE; B. WESTERLUND

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2009 vol. 1788 p. 1310 - 1310

0005-2736

phingolipids containing very long acyl chains are abundant in certain specialized tissues and minor components of plasma membranes in most mammalian cells. There are cellular processes in which these sphingolipids are required, and the function seems to be mediated through sphingolipid-rich membrane domains. This study was conducted to explore how very long acyl chains of sphingolipids influence their lateral distribution in membranes. Differential scanning calorimetry showed that 24:0- and 24:1-sphingomyelins, galactosylceramides and glucosylceramides exhibited complex thermotropic behavior and partial miscibility with palmitoyl sphingomyelin. The T(m) was decreased by about 20 degrees C for all 24:1-sphingolipids compared to the corresponding 24:0-sphingolipids. The ability to pack tightly with ordered and extended acyl chains is a necessity for membrane lipids to partition into ordered domains in membranes and thus the 24:1-sphingolipids appeared less likely to do so. Fluorescence