Molecular features of phospholipids that affect glycolipid transfer protein-mediated galactosylceramide transfer between vesicles

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Nylund M, Kjellberg MA, Molotkovsky JG, Byun HS, Bittman R, Mattjus P
Publication year: 2006
Journal: BBA - Biomembranes
Journal acronym: BBA-BIOMEMBRANES
Volume number: 1758
Issue number: 6
Start page: 807
End page: 812
Number of pages: 6
ISSN: 0005-2736


Abstract

The glycolipid transfer protein (GLTP)-mediated movement of galactosylceramide from model membrane donor vesicles to acceptor vesicles is sensitive to the membrane environment surrounding the glycolipid. GLTP can catalyze the transfer of a fluorescently labeled GSL, anthrylvinyl-galactosylceramide (AV-GalCer), from vesicles composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-pbosphocholine and dipalmitoylphosphatidylcholine matrices, but not from vesicles prepared from N-palmitoylsphingomyelin, regardless of the cholesterol content of the vesicles. In this study, we have examined the structural features of sphingomyelin (SM) that are responsible for its inhibition of the rate of GLTP-catalyzed transfer of AV-GalCer. The rate of glycolipid transfer was enhanced when the N-palmitoyl chain of SM was replaced with an N-oleoyl chain. Analogs of N-palmitoyl-SM in which the 4,5-double bond of the long-chain base is reduced or the 3-hydroxy group is removed did not inhibit GLTP-catalyzed transfer of AV-GalCer. When the donor vesicles were prepared with phosphatidyleholines or ether-linked phosphatidylcholine analogs, the transfer rates of AV-GalCer increased with increasing degree of unsaturation. The rate of AV-GalCer transfer was strongly dependent on the unsaturation degree of the acyl and/or alkyl chains. For ester-linked PCs, the transfer rate increased in the order DPPC < POPC < DOPC, which have 0, 1, and 2 cis double bonds, respectively.


Keywords

cholesterol, ether lipid, glycolipid transfer protein, glycosphingolipid, phosphatidylcholine, sphingomyelin, sphingomyelin analog

Last updated on 2019-22-09 at 02:57