MOLECULAR ARCHITECTURE OF ARABAN, GALACTOGLUCAN AND WELAN

The debranched plant polysaccharide araban exhibits fat mimic properti es. Among the Rhizobium family of bacterial polysaccharides, a galacto glucan, having a disaccharide repeating unit, is equally effective in root nodulation as the complex succinoglycan and similar polysaccharid es having branched octasaccharide repeating units. The branched polyme r welan, belonging to the gellan family of polysaccharides, has excell ent affinity for calcium and shows very high viscosity in aqueous solu tion up to 130 degrees C. The three-dimensional structures of these po lymers have been determined to varying degrees by using X-ray diffract ion and computer modeling methods. The structural details help to unde rstand the molecular basis of the functional properties of these polys accharides.