Acyl chain length affects ceramide action on sterol/sphingomyelin-rich domains

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Nybond S, Björkqvist YJE, Ramstedt B, Slotte JP
Publication year: 2005
Journal: BBA - Biochimica et Biophysica Acta
Volume number: 1718
Issue number: 1-2
Start page: 61
End page: 66


Abstract

The effects of ceramides with varying saturated N-linked acyl chains
(C2-C14) on cholesterol displacement from sphingomyelin-rich domains and
on the stability of ordered domains were studied. The bilayers examined
were made from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC),
D-erythro-N-palmitoyl-sphingomyelin (PSM),
D-erythro-N-acyl-sphingosine, and cholesterol (60:15:15:10 mol%,
respectively). Cholestatrienol (CTL) or
D-erythro-N-trans-parinoyl-sphingomyelin (tParSM) were used as reporter
molecules (at 1 mol%) for the ordered domains, and
1-palmitoyl-2-stearoyl-(7-doxyl)-sn-glycero-3-phosphocholine (7SLPC) as a
fluorescence quencher (30 mol%, replacing POPC) in the
liquid-disordered phase. The results indicate that the ceramide had to
have an N-linked acyl chain with at least 8 methylene units in order for
it to displace cholesterol from the sphingomyelin-rich domains at the
concentration used. The melting of the sphingomyelin-rich domain shifted
to higher temperatures (compared to the ceramide-free control) with C2,
C12 and longer chain ceramides, whereas C4-C10 ceramides led to domain
melting at lower temperatures than control. This study shows that
short-chain ceramides do not have the same effects on sterol- and
sphingomyelin-rich domains as naturally occurring longer-chain ceramides
have.


Keywords

cholesterol, model membrane

Last updated on 2019-19-08 at 03:21