title: Identification of a disialoganglioside (GD1a) containing terminal N-acetyl-9-O-acetylneuraminic acid in rat erythrocytes.
abstract: Gangliosides containing 350 micrograms of sialic acids were isolated from 2.85 X 10(11) rat erythrocytes and found to be mainly composed of GD1a and an unknown alkali-labile species which was converted to GD1a after treatment with ammonia. Smaller amounts of GM1 and Fuc-GM1 were also present. Identification of the sialic acids of the novel species by thin-layer chromatography, high performance liquid chromatography and gas-liquid chromatography--mass spectrometry revealed the presence of both N-acetylneuraminic acid and N-acetyl-9-O-acetyl-neuraminic acid in about equimolar amounts. Incubation of the isolated ganglioside with Vibrio cholerae sialidase released N-acetyl-9-O-acetyl-neuraminic acid. Non O-acetylated GM1 was identified as the only remaining ganglioside by thin-layer chromatography. Thus this novel ganglioside has the following structure: Neu5,9Ac2 alpha 2-3Gal beta 1-3GalNAc beta 1-4(Neu5Ac alpha-2-3)Gal beta 1-4Glc beta 1-1'Cer.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004912:Erythrocytes / Q000032:analysis*; D005732:Gangliosides / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D019158:N-Acetylneuraminic Acid; D051381:Rats; D012794:Sialic Acids / Q000032:analysis*; D014734:Vibrio cholerae / Q000201:enzymology
chemical_list: D005732:Gangliosides; D012794:Sialic Acids; C025676:9-O-acetyl-N-acetylneuraminic acid; D019158:N-Acetylneuraminic Acid