Carbohydrate chain structure

These data show that hemolytic activity depends upon both aglycon and carbohydrate chain structures. The presence of a linear tetrasaccharide fragment in carbohydrate chains is significant for the activity. Moreover, a sulfate group, attached to the C-4 of the... 

Nevertheless, the isolation of these metabolites was interesting in two respects. First, the structure of the thiazole glycol stimulated the research of functionalized carbohydrate chains as precursors of thiazole. Second, the thiazolecar-boxylic acid 40 can be secreted by derepressed cells in relatively high amounts, 0.24 nmol per mg of dried cells, which is nearly half the amount of synthesized thiamine. The presence of this free thiazolic derivative in the cells contrasts with... 

Kubelka, V., Altmann, F., Staudacher, E., Tretter, V., Marz, L., Hard, K., Kamerling, J.P. and Vliegenthart, F.G. (1993) Primary structure of the A-linked carbohydrate chains from honeybee venom phospholipase A2. European Journal of Biochemistry 213, 1193—1204. 

From a structural point of view, the carbohydrate template can have either furan or pyran rings although in some cases open chain structures can be formed. A large variety of aldopentoses (e.g. d- and L-arabinose, D-ribose, D-xylose), aldohexoses (e.g. D-glucose, D-mannose, D-galactose) as well as ketohexoses (e.g. D-fructose, L-sorbose) can be used as scaffolds. 

The carbohydrate chains of glycoproteins1 and glycolipids are commonly found as essential structures of such biologically important... 

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. 

One special feature in the interpretation of the quantitative results seems not to have been exploited in practical analysis, and it certainly deserves attention. The result of the methylation analysis is sometimes complex, and can reveal the occurrence of 10 to 20 different methylated sugars. In this situation, it is not easy to decide, by simple inspection of the analytical data, whether the result could be caused by one complex, carbohydrate chain, or by a structure containing several saccharide chains bound to a common aglycon. In addition, it is not always easy to decide whether the result could fit any natural structure, or mixture of structures, or whether the complex result is attributable to undermethylation. 

The structures of the carbohydrate chains of the various glycosaminoglycans have been described in considerable detail,289 291a and therefore only a few limited aspects concerned with these glycoproteins will be discussed. 

The Main Structural Features of the Carbohydrate Chains of Glycosaminoglycans... 

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