Structural determination of novel lacto-N-decaose and its monofucosylated analogue from human milk by electrospray tandem mass spectrometry and 1H NMR spectroscopy.
We have isolated and characterised two neutral oligosaccharides, one nonfucosylated and the other monofucosylated, from human milk that are based on the doubly branched lacto-N-decaose core. Their structures have been determined by a combined use of electrospray tandem mass spectrometry (ES-MS/MS) and NMR spectroscopy. The sequences of the three branches resulted from the double-branching, including the identity and location of the blood-group-related Lewis determinant and partial linkages, were elucidated by the unique method of high sensitivity negative-ion ES-MS/MS analysis. Their full structure assignment was completed by methylation analysis and 1H NMR. The monofucosylated lacto-N-decaose, Galbeta1-4(Fucalpha1-3)GlcNAcbeta1-6(Galbeta1-3GlcNAcbeta1-3)Galbeta1-4GlcNAcbeta1-6(Galbeta1-3GlcNAcbeta1-3)Galbeta1-4Glc is a novel sequence, whereas the nonfucosylated lacto-N-decaose, Galbeta1-4GlcNAcbeta1-6(Galbeta1-3GlcNAcbeta1-3)Galbeta1-4GlcNAcbeta1-6(Galbeta1-3GlcNAcbeta1-3)Galbeta1-4Glc, has not been isolated and identified as an individual oligosaccharide.
Chai
Wengang
W
MRC Glycosciences Laboratory, Imperial College Faculty of Medicine, Northwick Park and St. Mark's Campus, Watford Road, Harrow, Middlesex HA1 3UJ, United Kingdom. w.chai@imperial.ac.uk
Piskarev
Vladimir E
VE
Zhang
Yibing
Y
Lawson
Alexander M
AM
Kogelberg
Heide
H
D001789:Blood Group Antigens / Q000737:chemistry; D002240:Carbohydrate Sequence; D005260:Female; D006801:Humans; D008745:Methylation; D008895:Milk, Human / Q000737:chemistry*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization
D001789:Blood Group Antigens; D009844:Oligosaccharides