ISSN:
1573-4986
Keywords:
Helicobacter pylori
;
leucocytes
;
glycosphingolipids
;
trifluoroacetolysis
;
sialic acid
;
gas chromatography-mass spectrometry
;
linkage position
;
NeuAc, N-acetylneuraminic acid
;
NeuGc, N-glycolylneuraminic acid
;
Gal, galactose
;
GlcNAc, N-acetylglucosamine
;
GC/MS, gas chromatography mass spectrometry
;
DMSO, dimethyl sulphoxide
;
ether, diethyl ether
;
TFA, trifluoroacetic acid
;
TFAA, trifluoroacetic anhydride
;
TFAc, trifluoroacetyl
;
MALDI-TOF MS, matrix assisted laser desorptionionization time of flight mass spectrometry
;
6-SL, 6-sialyllactose
;
3-SL, 3-sialyllactose
;
SPG, sialylparagloboside
;
Me, methyl
;
FAB MS, fast atom bombardment mass spectrometry
;
EI MS, electron ionization mass spectrometry
;
DHB, 2,5-dihydroxybenzoic acid
;
TLC, thin-layer chromatography
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The human gastric pathogen Helicobacter pylori has been shown to bind to glycoconjugates of human leucocytes in a sialic acid-dependent way. In order to improve the identification of the binding epitope, a new technique was developed to analyze the ketosidic linkage position between a terminal sialic acid and the consecutive monosaccharide. Permethylation and reduction with LiAlH4 followed by trifluoroacetolysis in 1000:1 trifluoroacetic anhydride:trifluoroacetic acid (24 h, 100 °C) results in the cleavage of glycosidic but not ketosidic bonds. The disaccharide products were analyzed by gas chromatography-mass spectrometry and sialyl-3 or -6 position and NeuAc or NeuGc are identified by their separate retention times and mass spectra. The method was worked out on model saccharides and applied on five-sugar gangliosides (sialylparaglobosides) of human leucocytes. Radiolabeled Helicobacter pylori was shown to bind to the upper part, but not to the lower part, of the five-sugar interval of a mixture of gangliosides separated on a thin-layer chromatogram. Using a membrane blotting procedure the active and inactive bands were isolated and shown to be NeuAcα2-3- and NeuAcα2-6-paraglobosides, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006992616254
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