Isolation of three novel cholinergic neuron-specific gangliosides from bovine brain and their in vitro syntheses.
In the present study, three extremely minor but novel Chol-1 antigens, termed X1, X2, and X3 have been isolated from bovine brain gangliosides. Based on the results of sialidase degradation, TLC-immunostaining with anti-Chol-1 antibody and fast atom bombardment mass spectrometry, their chemical structures were identified as: III6NeuAc-GgOse4Cer (X1: GM1 alpha) III6NeuAc,II3NeuAc-GgOse4Cer (X2: GD1a alpha) III6NeuAc,II3NeuAc-NeuGc-GgOse4Cer (X3: GT1b alpha) The yields of GM1 alpha, GD1a alpha, and GT1b alpha, were approximately 150, 20, and 10 micrograms, respectively, from 10 g of the bovine brain ganglioside mixture. In conjunction with our previous observations, all gangliosides with anti-Chol-1 reactivity were found to contain a common sialyl alpha 2-6 N-acetylgalactosamine residue, indicating that this unique sialyl linkage is the specific antigenic determinant. We subsequently examined the biosynthesis of the three novel Chol-1 gangliosides using rat liver Golgi fraction as an enzyme source. The results showed that GM1 alpha, GD1a alpha, and GT1b alpha were synthesized from asialo-GM1, GM1a, and GD1b, respectively, by the action of a GalNAc alpha 2-6sialyltransferase.
Irie
F
F
Laboratory for Cellular GlycoBiology, Institute of Physical and Chemical Research (RIKEN), Hirosawa, Wako-shi, Saitama, Japan.
Kurono
S
S
Li
Y T
YT
Seyama
Y
Y
Hirabayashi
Y
Y
D000818:Animals; D001921:Brain / Q000502:physiology*; D001923:Brain Chemistry; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005732:Gangliosides / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification*; D006056:Golgi Apparatus / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009439:Neuraminidase; D009474:Neurons / Q000502:physiology*; D051381:Rats; D012799:Sialyltransferases / Q000378:metabolism*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D005732:Gangliosides; D012799:Sialyltransferases; D009439:Neuraminidase; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase