2 research outputs found
Push–Pull Mechanism for Lipid Raft Formation
A quantitative assessment has been
made of the interaction between
exchangeable mimics of 1-palmitoyl-2-oleoyl-<i>sn</i>-glycero-3-phosphocholine
(POPC) and cholesterol in the liquid-ordered (<i>l</i><sub>0</sub>) and the liquid-disordered (<i>l</i><sub>d</sub>) states using the nearest-neighbor recognition (NNR) method. This
assessment has established that these lipids mix ideally in the <i>l</i><sub>0</sub> phase (i.e., they show no net attraction or
repulsion toward each other) but exhibit repulsive interactions in
the <i>l</i><sub>d</sub> phase. The implications of these
findings for the interactions between unsaturated phospholipids and
cholesterol in eukaryotic cell membranes are briefly discussed
Stimulated Release of Cholesterol from Liposomal Membranes by a PEGylated Phospholipid
PEGylated phospholipids are commonly used to increase
the blood-circulation
time of liposomes by providing a steric barrier around them. This
paper documents a fundamentally new property of these lipidsî—¸an
ability to stimulate the release of cholesterol from phospholipid
membranes. Evidence for such stimulation has been obtained by measuring
the transport of dehydroergosterol (DHE), a fluorescent simulant of
cholesterol, from donor liposomes made from 1-palmitoyl-2-oleoyl-<i>sn</i>-glycero-3-phosphocholine (POPC), 1,2-distearoyl-<i>sn</i>-glycero-3-phosphoethanolamine-<i>N</i>-[methoxyÂ(polyethylene
glycol)-2000 (DSPE-PEG<sub>2000</sub>), and DHE to acceptor liposomes
made from POPC, 1-palmitoyl-2-oleoyl-<i>sn</i>-glycero-3-phosphoglycerol
(POPG), and cholesterol. The potential of PEGylated lipids to serve
as novel cholesterol-lowering agents is briefly discussed