Spontaneous transfer of gangliotetraosylceramide between phospholipid vesicles

Journal Article · Tue Jul 16 00:00:00 EDT 1985 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00336a042· OSTI ID:6258990

Brown, R E; Sugar, I P; Thompson, T E

The transfer kinetics of the neutral glycosphingolipid gangliotetraosylceramide (asialo-GM1) were investigated by monitoring tritiated asialo-GM1 movement from donor to acceptor vesicles. Two different methods were employed to separate donor and acceptor vesicles at desired time intervals. In one method, a negative charge was imparted to dipalmitoylphosphatidylcholine donor vesicles by including 10 mol% dipalmitoylphosphatidic acid. Donors were separated from neutral dipalmitoylphosphatidylcholine acceptor vesicles by ion-exchange chromatography. In the other method, small, unilamellar donor vesicles and large, unilamellar acceptor vesicles were coincubated at 45 degrees C and then separated at desired time intervals by molecular sieve chromatography. The majority of asialo-GM1 transfer to acceptor vesicles occurred as a slow first-order process with a half-time of about 24 days assuming that the relative concentration of asialo-GM1 in the phospholipid matrix was identical in each half of the donor bilayer and that no glycolipid flip-flop occurred. Asialo-GM1 net transfer was calculated relative to that of ( UC)cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. A nearly identical transfer half-time was obtained when the phospholipid matrix was changed from dipalmitoylphosphatidylcholine to palmitoyloleoylphosphatidylcholine. Varying the acceptor vesicle concentration did not significantly alter the asialo-GM1 transfer half-time. This result is consistent with a transfer mechanism involving diffusion of glycolipid through the aqueous phase rather than movement of glycolipid following formation of collisional complexes between donor and acceptor vesicles. (Abstract Truncated)

• Research Organization: Univ. of Virginia School of Medicine, Charlottesville
• OSTI ID: 6258990
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 15; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CATTLE
CELL CONSTITUENTS
CHEMISTRY
CHOLINE
CHROMATOGRAPHY
DIFFUSION
DOMESTIC ANIMALS
DRUGS
ESTERS
GANGLIOSIDES
HEXADECANOIC ACID
HYDROXY COMPOUNDS
ION EXCHANGE CHROMATOGRAPHY
KINETICS
LABELLED COMPOUNDS
LIPIDS
LIPOSOMES
LIPOTROPIC FACTORS
MAMMALS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
PHOSPHOLIPIDS
QUATERNARY COMPOUNDS
REACTION KINETICS
RUMINANTS
SACCHARIDES
SEPARATION PROCESSES
TRITIUM COMPOUNDS
VERTEBRATES