Structure determination of five sialylated trisaccharides with core types 1, 3 or 5 isolated from bovine submaxillary mucin.
In this study we have investigated the structures of five sialylated trisaccharides released from bovine submaxillary mucin by alkaline borohydride treatment and isolated by high-performance liquid chromatography. Three of the trisaccharides contained NeuAc while two contained NeuGc. One oligosaccharide contained core-type 1, two contained core-type 3 and two contained core-type 5. The structures, determined by a combination of one- and two-dimensional 1H-NMR spectroscopy at 270 MHz and methylation analysis involving gas-liquid chromatography/mass spectrometry, were as follows: A4b, GalNAc alpha(1----3) [NeuAc alpha(2----6)]GalNAcol; A4c, GlcNAc beta(1----3)[NeuAc alpha(2----6)]GalNAcol; A4d, Gal beta(1----3)[NeuAc alpha(2----6)]GalNAcol; A4e, GalNAc alpha(1----3)-[NeuGc alpha(2----6)]GalNAcol; A4f, GlcNAc beta(1----3)[NeuGc alpha (2----6)]GalNAcol. The oligosaccharides occurred in the approximate molar ratios 1.0:12.0:0.3:0.2:2.0. This is the first report of oligosaccharides containing core-type 5 and of the occurrence of oligosaccharides A4b, A4e, and A4f in bovine submaxillary mucin. 1H-NMR data for structure A4e, which is a novel structure, are presented for the first time.
Savage
A V
AV
Chemistry Department, University College, Galway, Ireland.
Donoghue
C M
CM
D'Arcy
S M
SM
Koeleman
C A
CA
van den Eijnden
D H
DH
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009077:Mucins / Q000302:isolation & purification*; D013363:Submandibular Gland / Q000737:chemistry*; D014312:Trisaccharides / Q000737:chemistry / Q000302:isolation & purification*
D009077:Mucins; D014312:Trisaccharides