Characterization of antigens from Aspergillus fumigatus. II. Fractionation and electrophoretic, immunologic, and biologic activity.

Mycelial extracts of Aspergillus fumigatus grown in completely synthetic medium were fractionated by precipitation with ammonium sulfate, by ion-exchange chromatography, and by gel filtration. The fractions were characterized chemically, by analytic polyacrylamide gel electrophoresis, and by tests for serologic and biologic activity. The distribution of the antigens in the fractions was determined by double diffusion in gel and fused-rocket immunoelectrophoresis. Activity greater than that of the parent mycelial extract serologically, in guinea pig skin tests, and in in vitro lymphocyte transformation was observed with one fraction that was found in the 75 per cent ammonium sulfate precipitable portion and was eluted early by gel filtration. Another ammonium sulfate-precipitable component and one that was not precipitable at 75 per cent ammonium sulfate, but was firmly bound by ion-exchange columns, was found to have activity equal to unfractionated mycelial extract. These fractions were also active by a radioallergosorbent test for IgE. A carbohydrate component comprising almost 40 per cent of mycelial extract was found to be devoid of any immunologic activity.