Galactans branching

The structure that appears to be important for the effect on the complement system is most probably the complex galactan ohgomer being composed of separate 1,3- and 1,6-hnked galactose chains with branch points being of 1,3,6 nature. These units have been proposed as the active sites for... 

Attached to this galactan are branched penta-D-arabinose units ... 

Cell walls of mycobacteria are composed of a peptidoglycan with covalently attached galactan chains. Branched chains of arabinan, a polymer of the furanose ring form of arabinose with covalently attached mycolic acids, are glycosidically linked to the galactan.327 Shorter glycopeptidolipids, containing... 

The hemicelluloses are polymolecular, random-coil, often branched hetero-glycans interspersed with cellulose microfibrils and starch granules in vivo. Glucose, xylose, and arabinose are the prominent sugars, although lesser quantities of galactan, mannan, etc., and minor concentrations of acetic, ferulic and uronic acids, etc., are in evidence. Heterogeneity extends to dimensions and conformation. 

The above structure is very different from that of the galactan associated with pectin in the seeds of Lupinus albus. This was shown to have a chain-length of 120 units.64 As no molecular weight measurements have been carried out on this material, it is not known whether the molecule is linear or branched. 

Arabo-galactan from larch wood Sedimentation and Diffusion 16,000 A highly branched molecule 62... 

The existence of the mixture of polysaccharides was confirmed by Hirst and co-workers, 3 who obtained two fractions from the methylated t-galactan, one containing only a trace of pentose, whilst the other was rich in pentosan. The structure of the arabogalactan portion which was investigated was found to be highly branched. 

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