Isolation and structural elucidation of a novel type of ganglioside, deaminated neuraminic acid (KDN)-containing glycosphingolipid, from rainbow trout sperm. The first example of the natural occurrence of KDN-ganglioside, (KDN)GM3.
Rainbow trout sperm contained almost exclusively monoanionic ganglioside fraction as a major acidic glycosphingolipid. Two monoacidic gangliosides were isolated and purified in this study and designated as sperm ganglioside 1 and 2 (sg-1 and sg-2). The two gangliosides, sg-1 and sg-2, contained the same neutral sugars, galactose and glucose in molar ratio of 1:1 and no GalNAc except for the presence of N-acetyl-neuraminic acid (NeuAc) in sg-1 and deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in sg-2. The complete structures of these gangliosides were determined by a combination of methylation analysis, fast atom bombardment mass spectrometry, 400-MHz one- and two-dimensional 1H nuclear magnetic resonance spectroscopy, fatty acid analysis, and endoglycoceramidase digestion NeuAc alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-1 [(NeuAc)GM3] KDN alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-2 [(KDN)GM3] where, for both sg-1 and sg-2, the ceramide moieties (Cer) were found to be made up of 4-sphingenine and mainly C16:0 fatty acid (palmitate; 95%) with a minor amount of C24:1 fatty acyl chain (nervonate, 5%). The structure of sg-2 is novel and represents the first example of a new class of gangliosides, i.e. KDN-gangliosides.
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
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Song
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Kitajima
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Inoue
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Inoue
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005732:Gangliosides / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008969:Molecular Sequence Data; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013094:Spermatozoa / Q000737:chemistry*; D014337:Trout
D005732:Gangliosides; C071655:sperm ganglioside 1; C071656:sperm ganglioside 2