Comparison between Ca2+-induced scrambling of various fluorescently labelled lipid analogues in red blood cells.
Treatment of red blood cells with calcium and ionomycin causes activation of the lipid scramblase, a putative membrane protein catalysing flip-flop of (phospho)lipids. Various fluorescent 1-oleoyl-2-[6(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino] caproyl (C(6)-NBD) analogues were tested for transbilayer movement across the plasma membrane of red blood cells. Among these phospholipid analogues were phosphatidylgalactose, phosphatidylmaltose and phosphatidylmaltotriose, which were obtained from C(6)-NBD-phosphatidylcholine by phospholipase D-catalysed transphosphatidylation. The inward movement after the onset of scrambling was monitored by extraction of the non-internalized probe with BSA. We demonstrate that both the amino group and the size of the headgroup determine the kinetics of lipid scrambling, and that lipids with a ceramide backbone migrate much more slowly than glycerophospholipids with the same headgroup.
Dekkers
David W C
DW
Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Comfurius
Paul
P
Bevers
Edouard M
EM
Zwaal
Robert F A
RF
D009327:4-Chloro-7-nitrobenzofurazan / Q000031:analogs & derivatives* / Q000097:blood*; D002118:Calcium / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000493:pharmacokinetics*; D020404:Glycerophospholipids / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D015759:Ionomycin / Q000494:pharmacology*; D007700:Kinetics; D008051:Lipid Bilayers; D008563:Membrane Lipids / Q000097:blood; D010739:Phospholipase D / Q000097:blood; D013329:Structure-Activity Relationship
D005456:Fluorescent Dyes; D020404:Glycerophospholipids; D008051:Lipid Bilayers; D008563:Membrane Lipids; D015759:Ionomycin; D010739:Phospholipase D; D009327:4-Chloro-7-nitrobenzofurazan; D002118:Calcium