Structure of novel gangliosides, deaminated neuraminic acid (KDN)-containing glycosphingolipids, isolated from rainbow trout ovarian fluid

Biochemistry. 1993 Sep 7;32(35):9221-9. doi: 10.1021/bi00086a030.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrate Sequence
  • Deamination
  • Female
  • Follicular Fluid / chemistry*
  • Gangliosides / chemistry*
  • Glycosphingolipids / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Sequence Analysis
  • Spectrometry, Mass, Fast Atom Bombardment
  • Sugar Acids / analysis*
  • Trout*

Substances

  • Gangliosides
  • Glycosphingolipids
  • Sugar Acids
  • 3-deoxyglycero-galacto-nonulosonic acid