Exposure of major neutral glycolipids in red cells to galactose oxidase. Effect of neuraminidase.
The exposure of several major red-cell glycolipids to galactose oxidase was studied by oxidizing the cells with the enzyme and reducing them with NaB2H4. After isolation, the deuterium label was detected by mass fragmentography. 60-70% globoside in human and porcine erythrocytes was exposed as measured by this method. In contrast, asialo-GM2 in guinea-pig erythrocytes and Forssman glycolipid in sheep erythrocytes were mainly in a cryptic state. Neuraminidase treatment increased the incorporation of deuterium label to asialo-GM2 4-8-fold. A similar effect was seen in Forssman glycolipid when sheep red cells were labeled with the neuraminidase/galactose oxidase/NaB3H4 method. In contrast, the increase in labeling was only about 10-40% in porcine and human globosides, which were efficiently exposed to galactose oxidase already in native red cells.
D000818:Animals; D001894:Borohydrides / Q000494:pharmacology; D002855:Chromatography, Thin Layer; D003903:Deuterium; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005227:Fatty Acids / Q000097:blood; D005692:Galactose Oxidase / Q000494:pharmacology*; D005732:Gangliosides; D005915:Globosides / Q000097:blood; D006017:Glycolipids / Q000097:blood*; D006028:Glycosphingolipids / Q000097:blood; D006168:Guinea Pigs; D006801:Humans; D008565:Membrane Proteins / Q000097:blood; D009439:Neuraminidase / Q000494:pharmacology*; D010084:Oxidation-Reduction; D012756:Sheep; D013552:Swine
D001894:Borohydrides; D005227:Fatty Acids; D005732:Gangliosides; D005915:Globosides; D006017:Glycolipids; D006028:Glycosphingolipids; D008565:Membrane Proteins; C038244:ganglio-N-triaosylceramide; C010163:Forssman glycolipid; C025364:sodium borohydride; D003903:Deuterium; D005692:Galactose Oxidase; D009439:Neuraminidase