Specificity of mild periodate oxidation of oligosaccharide-alditols: relevance to the analysis of the core-branching pattern of O-linked glycoprotein oligosaccharides.
The specificity of mild periodate oxidation of 3- and 6-substituted 2-acetamido-2-deoxy-D-galactitols and 4- and 6-substituted D-glucitols has been investigated. The products were reacted with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine and the derivatives were analysed by application of liquid secondary-ion mass spectrometry directly to the TLC plates. There was > 95% specificity of cleavage of the C-4-C-5 bond (threo-diol) for the GalNAcol derivatives. The major sites of oxidation for the Glcol derivatives also involved threo-diols. For alpha-Neu5Ac-(2-->6)-GalNAcol, approximately 30% of the products of oxidation involved the sialic acid side chain, and approximately 60% were cleaved at the C-4-C-5 bond of the GalNAcol moiety. The mild periodate oxidation reaction forms part of a strategy for determining the patterns of branching of the cores of O-linked glycoprotein oligosaccharides and other oligosaccharide-alditols.
Chai
W
W
Section of Clinical Mass Spectrometry, M.R.C. Clinical Research Centre, Harrow, Middlesex, United Kingdom.
Stoll
M S
MS
Cashmore
G C
GC
Lawson
A M
AM
D002240:Carbohydrate Sequence; D002855:Chromatography, Thin Layer; D006023:Glycoproteins / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D010084:Oxidation-Reduction; D010504:Periodic Acid / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D013402:Sugar Alcohols / Q000737:chemistry*
D006023:Glycoproteins; D009844:Oligosaccharides; D010714:Phosphatidylethanolamines; D013402:Sugar Alcohols; D010504:Periodic Acid; C007510:1,2-dipalmitoyl-3-phosphatidylethanolamine