Structure of novel gangliosides, deaminated neuraminic acid (KDN)-containing glycosphingolipids, isolated from rainbow trout ovarian fluid.
Two acidic glycosphingolipids were isolated and purified from rainbow trout ovarian fluid. They were designated as ovarian fluid gangliosides ofg-2a and ofg-2b. Both of these glycolipids were found to contain glucose, galactose, and N-acetylgalactosamine in a molar ratio of 1:2:1, but they differ by the presence of 2 mol of deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in ofg-2a and 1 mol each of KDN and 9-O-acetyl-KDN in ofg-2b. On the basis of composition analysis, methylation analysis, mild acid hydrolysis, fast atom bombardment mass spectrometry (FABMS), 400-MHz 1H nuclear magnetic resonance spectroscopy, and immunochemical analysis using a monoclonal antibody (mAb.kdn3G), the complete structures of these gangliosides were determined to be KDN alpha 2-->3Gal beta 1-->3GalNAc beta 1-->4(KDN alpha 2-->3)Gal beta 1-->4Glc beta 1-->Cer for ofg-2a [(KDN)GD1a] and 9-O-AcKDN alpha 2-->3Gal beta 1-->3GalNAc beta 1-->4(KDN alpha 2-->3)Gal beta 1-->4Glc beta 1-->Cer for ofg-2b [(KDN)GD1a(OAc+)]. The ceramide moieties (Cer) in both ofg-2a [(KDN)GD1a] and ofg-2b [(KDN)GD1a(OAc+)] were found by combining of the results from fatty acid analysis and FABMS measurements to be made up of 4-sphingenine and mainly a C24:1 fatty acyl chain (nervonate). The structures of ofg-2a and ofg-2b are novel, and they represent the second example of naturally occurring KDN-gangliosides. Mild acid hydrolysis of both ofg-2a and ofg-2b resulted in formation of (KDN)GM1a.
Song
Y
Y
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
Kitajima
K
K
Inoue
S
S
Muto
Y
Y
Kasama
T
T
Handa
S
S
Inoue
Y
Y
D000818:Animals; D002240:Carbohydrate Sequence; D003641:Deamination; D005260:Female; D015571:Follicular Fluid / Q000737:chemistry*; D005732:Gangliosides / Q000737:chemistry*; D006028:Glycosphingolipids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D017421:Sequence Analysis; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013400:Sugar Acids / Q000032:analysis*; D014337:Trout
D005732:Gangliosides; D006028:Glycosphingolipids; D013400:Sugar Acids; C050008:3-deoxyglycero-galacto-nonulosonic acid