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

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Nylund M, Kjellberg MA, Molotkovsky JG, Byun HS, Bittman R, Mattjus P
Publiceringsår: 2006
Tidskrift: BBA - Biomembranes
Tidskriftsakronym: BBA-BIOMEMBRANES
Volym: 1758
Nummer: 6
Artikelns första sida, sidnummer: 807
Artikelns sista sida, sidnummer: 812
Antal sidor: 6
ISSN: 0005-2736


Abstrakt

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.


Nyckelord

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

Senast uppdaterad 2019-08-12 vid 03:30