Spontaneous transfer of ganglioside GM/sub 1/ between phospholipid vesicles
The transfer kinetics of the negatively charged glycosphingolipid II/sup 3/-N-acetylneuraminosyl-gangliotetraosylceramide (GM/sub 1/) were investigated by monitoring tritiated GM/sub 1/ movement between donor and acceptor vesicles. After appropriate incubation times at 45 /sup 0/C, donor and acceptor vesicles were separated by molecular sieve chromatography. Donors were small unilamellar vesicles produced by sonication, whereas acceptors were large unilamellar vesicles produced by either fusion or ethanol injection. Initial GM/sub 1/ transfer to acceptors followed first-order kinetics with a half-time of about 40 h assuming that GM/sub 1/ is present in equal mole fractions in the exterior and interior surfaces of the donor vesicle bilayer and that no glycolipid flip-flop occurs. GM/sub 1/ net transfer was calculated relative to that of (/sup 14/C)cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. Factors affecting the GM/sub 1/ interbilayer transfer rate included phospholipid matrix composition, initial GM/sub 1/ concentration in donor vesicles, and the GM/sub 1/ distribution in donor vesicles with respect to total lipid symmetry. The findings provide evidence that GM/sub 1/ is molecularly dispersed at low concentrations within liquid-crystalline phospholipid bilayers.
- Research Organization:
- Univ. of Virginia School of Medicine, Charlottesville
- OSTI ID:
- 5880472
- Journal Information:
- Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 26:17; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
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Ganglioside GM/sub 1/ spontaneous transfer between phospholipid vesicles
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59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHROMATOGRAPHY
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GANGLIOSIDES
GAS CHROMATOGRAPHY
GLYCOLIPIDS
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LABELLED COMPOUNDS
LIPIDS
MEMBRANE TRANSPORT
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MONOCARBOXYLIC ACIDS
OLEIC ACID
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ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
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