Novel polysialogangliosides of skate brain structural determination of tetra, penta and hexasialogangliosides with a NeuAc-GalNAc linkage.
The gangliosides in the brain of a cartilaginous fish, skate (Bathyraja smirnovi), have been isolated and characterized by means of methylation analysis, antibody binding, enzymatic hydrolysis and MALDI-TOF MS. In addition to gangliosides with known structures (GM2, fucosyl-GM1, GD3, GD2, GT3 and GT2), five polysialogangliosides were isolated and characterized as having the following structures. (1) IV3NeuAc, III6NeuAc, II3NeuAc-Gg4Cer; (2) IV3NeuAc2, III6NeuAc, II3NeuAc-Gg4Cer; (3) IV3NeuAc, III6NeuAc, II3NeuAc2-Gg4Cer; (4) IV3NeuAc, III6NeuAc, II3NeuAc3-Gg4Cer; and (5) IV3NeuAc2, III6NeuAc, II3NeuAc3-Gg4Cer. These structures are 'hybrid-type' which comprise combinations of alpha-series and either a, b or c-series structures. Three gangliosides (2), (4) and (5), were novel. The main features of the ganglioside composition of skate brain were an abundance of gangliotriaosyl species, a lack of gangliotetraosyl species (except fucosyl-GM1), and an abundance of hybrid-types. These characteristics closely resemble those in shark brain which we reported previously [Nakamura, K., Tamai, Y. & Kasama, T. (1997) Neurochem. Int. 30, 593-604]. Two of the hybrid-type gangliosides (1) and (4), were examined for their neuritogenic activity toward cultured neuronal cells (Neuro-2A), and were found to have more potent activity than nonhybrid-type gangliosides such as GM1.
Nakamura
K
K
Department of Biochemistry, Kitasato University School of Medicine, Kanagawa. nakam@kitasato-u.ac.jp
Kojima
H
H
Suzuki
M
M
Suzuki
A
A
Tamai
Y
Y
D000116:Acetylgalactosamine; D000818:Animals; D001923:Brain Chemistry; D002240:Carbohydrate Sequence; D002417:Cattle; D004284:Dogfish; D005732:Gangliosides / Q000737:chemistry* / Q000302:isolation & purification; D000882:Haplorhini; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D012860:Skates, Fish; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D005732:Gangliosides; C025447:sialogangliosides; D019158:N-Acetylneuraminic Acid; D000116:Acetylgalactosamine