Characterization of a O-fatty-acylated sulfatide from equine brain.
A sulfatide, O-fatty-acylated 3-sulfogalactosylceramide at C6-O on galactoside, was isolated from equine brain and the chemical structure was characterized by proton NMR and MS. The O-acylation site of the acylated sulfatide was determined by the down-field shift of protons attached to a carbon having an O-acyl group in the NMR spectrum and by analysis of a partially methylated derivative before and after acetalization of the intact sulfatide using GC-MS. The O-acyl chain length was determined by GLC, revealing that it exclusively had palmitoyl and stearoyl residues as the major fatty acids. The enzymatic conversion to the O-acyl sulfatide was further examined using equine brain microsomes as an enzyme source and different lipid substrates, resulting in O-acylation of 3-sulfogalactosylceramide from stearoyl CoA, while 6-O-acyl galactosylceramide was not O-sulfated from phosphoadenosine phosphosulfate. The results were supported by the comparably different N-linked fatty acid components between two lipid substrates, in which the component of 6-O-acyl sulfatide was mostly similar to that of sulfatide, but not to 6-O-acyl galactosylceramide.
Department of Chemistry, Sapporo Medical University School of Medicine, Japan.
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T
Mikami
K
K
Tsuchihashi
M
M
Kashiwagi
Y
Y
Yachida
T
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Daino
K
K
Hashi
T
T
Akino
S
S
Gasa
D000215:Acylation; D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry; D002849:Chromatography, Gas; D005227:Fatty Acids / Q000032:analysis*; D006028:Glycosphingolipids / Q000737:chemistry*; D006736:Horses; D008861:Microsomes / Q000201:enzymology; D019906:Nuclear Magnetic Resonance, Biomolecular; D019308:Palmitic Acid / Q000032:analysis; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013229:Stearic Acids / Q000032:analysis; D013433:Sulfoglycosphingolipids / Q000032:analysis*
D005227:Fatty Acids; D006028:Glycosphingolipids; D013229:Stearic Acids; D013433:Sulfoglycosphingolipids; D019308:Palmitic Acid; C031183:stearic acid