Novel polysialogangliosides of skate brain

• DOI: 10.1046/j.1432-1327.2000.01590.x
• Publication Date: 2003-03-11T17:52:08Z
• Authors: Kazuo Nakamura; Hisako Kojima; Minoru Suzuki; Akemi Suzuki; Yoichi Tamai
• Keywords: Brain Chemistry; 0301 basic medicine; Acetylgalactosamine; Molecular Sequence Data; Haplorhini; N-Acetylneuraminic Acid; 03 medical and health sciences; Carbohydrate Sequence; Dogfish; Gangliosides; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Animals; Cattle; Skates, Fish

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 α‐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.