ISOLATION AND CHARACTERIZATION OF A UNIQUE SULFATED GANGLIOSIDE, SULFATED GM1A, FROM RAT-KIDNEY

A novel class of sulfoglycosphingolipid, a sulfate analog of gangliosi de, was isolated from mammals for the first time, This sulfated gangli oside was purified from rat kidney by column chromatographies on anion exchangers and silica beads, One-dimensional H-1 NMR, compositional a nd permethylation analyses showed that this glycolipid has a Gg(4)Cer core with 1 mol each of sulfate ester and N-glycolylneuraminic acid (N euGc) at C-3 of galactose, The major ceramide consisted of nonhydroxy fatty acids (24:0 and 22:0) and 4-hydroxysphinganine (t18:0), deduced from the compositional analysis and negative liquid secondary ion mass spectrometry (LSIMS), Mild acid hydrolysis and solvolysis produced co mpounds which correspond to Gg(4)Cer IV3-sulfate (SM1b) and II(3)NeuCc alpha-Gg(4)Cer (GM1a (NeuGc)), respectively, The abundant ions charac teristic for sulfated mono-and disaccharides in high-energy collision- induced dissociation (CID) spectra mere consistent with the structure at the non-reducing terminus, HSO3-O-HexO-HexNAc- rather than the alte rnative structure, NeuGc-O-Hex-O-HexNAc-. The two-dimensional H-1 NMR further evidenced the presence of a 3-O-sulfated galactose in the mole cule. From these results the complete structure was proposed to be HSO 3-3Gal beta-3GalNAc beta-4(NeuGc alpha-3)Gal beta-4Glc beta-1Cer (II(3 )NeuGc alpha-Gg(4)Cer IV3-sulfate).