A novel heptasialosyl c-series ganglioside in embryonic chicken brain: its structure and stage-specific expression.
A ganglioside of unknown structure (ganglioside X) was purified from chicken brain at embryonic day 12 (E12) and characterized for its structure. Ganglioside X was reactive with a monoclonal antibody A2B5 and migrated below GH1c on thin-layer chromatography (TLC). Extensive treatment of ganglioside X with Clostridium perfringens sialidase produced a single ganglioside product. This ganglioside was identified as GM1 based upon its chromatographic mobility and reactivity to cholera toxin B subunit and anti-GM1 antibody. Partial hydrolysis of ganglioside X by sialidase generated several degradation products including GH1c, GP1c, and GQ1c. Electrospray ionization (ESI)-mass spectrometry (MS) of the permethylated derivative of ganglioside X produced a triple-charged parent ion peak at m/z 1355, which corresponded with the gangliotetraose oligosaccharide structure having seven sialic acids and ceramide with the molecular mass of 566 (as non-methylated form). Collision-induced dissociation (CID)-MS(2) showed fragment ions including those at m/z 1066 and 1931; these two ions matched the structures of (NeuAc)(3)-Gal-Glc-Cer and (NeuAc)(4)-Gal-GalNAc, respectively. These structures were confirmed by CID-MS(3) of the corresponding peaks. Based upon these findings, the structure of ganglioside X was identified as NeuAc-NeuAc-NeuAc-NeuAc-Galbeta1-3GalNAcbeta1-4(NeuAc-NeuAc-NeuAcalpha2-3)Galbeta1-4Glcbeta1-1'Cer. This ganglioside was designated as GS1c. A developmental study demonstrated that GS1c was expressed in chicken brain during a period from E6 to E13 and thereafter decreased rapidly in its concentration. The present study suggests that GS1c may play a specific role in early development of chicken brain.
Saito
Megumi
M
Department of Clinical Pharmacology and Therapeutics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan. saitom@ys2.u-shizuoka-ken.ac.jp
Kitamura
Hisayo
H
Sugiyama
Kiyoshi
K
D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002645:Chickens; D002855:Chromatography, Thin Layer; D005732:Gangliosides / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D006028:Glycosphingolipids / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009439:Neuraminidase
C011258:G(A1) ganglioside; D005732:Gangliosides; D006028:Glycosphingolipids; C038700:ganglioside, Gx; D009439:Neuraminidase