Oxidation of glycolipids in liposomes by galactose oxidase.
Small unilamellar phosphatidylcholine vesicles containing globo-series glycolipids were labeled by the galactose oxidase/NaB[3H]4 procedure. The major glycolipid of human red cells, globoside, was the best substrate for galactose oxidase both in vesicles and in tetrahydrofuran-containing buffer. The oxidation rates of membrane-bound ceramide trihexoside and Forssman glycolipid were one-fourth and one-tenth, respectively, of the oxidation rate of globoside. Membrane-bound ceramide dihexoside was not a substrate for galactose oxidase, although it was readily oxidized in tetrahydrofuran-containing buffer. Soluble sialoglycoproteins and membrane-incorporated glycophorin A stimulated the oxidation of globoside-containing vesicles, whereas membrane-bound GD1a ganglioside had no effect on globoside oxidation.
Lampio
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A
Department of Biochemistry, University of Helsinki, Finland.
Siissalo
I
I
Gahmberg
C G
CG
D000818:Animals; D002021:Buffers; D002849:Chromatography, Gas; D005692:Galactose Oxidase; D005915:Globosides / Q000032:analysis; D006017:Glycolipids / Q000032:analysis*; D006021:Glycophorins / Q000494:pharmacology; D006801:Humans; D008081:Liposomes / Q000032:analysis*; D008563:Membrane Lipids / Q000032:analysis*; D008854:Microscopy, Electron; D010084:Oxidation-Reduction / Q000187:drug effects; D010713:Phosphatidylcholines / Q000032:analysis; D012795:Sialoglycoproteins / Q000494:pharmacology; D014281:Trihexosylceramides / Q000032:analysis
D002021:Buffers; D005915:Globosides; D006017:Glycolipids; D006021:Glycophorins; D008081:Liposomes; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D012795:Sialoglycoproteins; D014281:Trihexosylceramides; D005692:Galactose Oxidase