Glycans characterization

Core 1 O-glycan Ab3T Tn syndrome Absence of Core I O-glycan characterized by thrombocytopenia, leukopenia and au autoimmume hemolytic anemia caused by auto-anti-Tn antibodies. 

Next to MALDI-MS, the use of ESt-MS is important in oligosaccharide and glycan characterization, especially because it can be combined with on-line LC separation of complex mixtures. The most important LC methods in glycan and oligosaccharide separation are HILIC [184], HPAEC, and, after derivatization by reductive amination with 2-aminobenzamide or 2-aminoacridone, RPLC on either Cjg or porous graphitized carbon materials [185]. 

Parasitism by T. spiralis has been a subject of scientific interest for over 150 years. Recently, considerable attention has been paid to the parasite by immunologists interested in immunity to nematodes in general, and mucosal immunity in particular. It has been shown that glycan-specific antibodies are highly effective mediators of host defence against intestinal 7. spiralis infection. Protective monoclonal antibodies have been used to elucidate mechanisms of worm expulsion, as well as to identify molecules that the parasite uses to create its niche. In the future, detailed characterization of these molecules and their functions should afford additional insights into parasitism by Trichinella spiralis, and possibly also by other types of pathogen. 

Fig. 15.5. Structures of A/-linked glycans from several different species of parasitic nematodes, illustrating both similarities with mammalian glycans (compare with Figs 15.1 and 15.2) and features unique to nematodes (e.g. tyvelose and PC capping and novel core fucosylation). The filarial nematode glycans are believed to be substituted with charged residues, which are not yet characterized.

Methylation analysis (and its different applications) is one of the most widely used methods in the structural characterization of carbohydrate chains (reviewed in refs, 5-8). In the present article, the progress achieved, and the problems encountered, in the analysis of animal glycolipids and glycoproteins are discussed, although many of the topics also concern the analysis of carbohydrate chains in general. Emphasis is laid on the efforts made to find ways to lessen the amounts of sample needed for the analysis, because only small amounts of glycan samples isolated from biological sources are often available. 

Wallace A., Boyce J., and Balland A. (2002), Structural Characterization of Man-nose-6-phosphate-containing glycans by tandem mass spectrometry, IBC s Conference on The Impact of Post-Translational and Chemical Modifications on Protein Therapeutics, San Diego, CA. 

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