Isolation and characterization of a novel polysaccharide as a possible allergen occurring in wheat flour.

A new polysaccharide with a molecular weight of 5.0 x 10(4) was isolated as a possible wheat allergen from a water-soluble fraction of flour by affinity chromatography and gel filtration. The isolated polysaccharide was found to be a possible wheat allergen, as it bound specifically to IgE antibodies in the sera of patients allergic to the water-soluble fraction of flour. Chemically, the sugar moiety of the polysaccharide consisted of D-glucose and D-mannose with beta-1,4-linkages in a molar ratio of 4.4:1. Since this mannoglucan is thought to be stable in our body, it would act as a remaining allergen to cause a long-lasting allergic reaction to wheat flour.