Preparation of Aspergillus fumigatus antigens and their analysis by two-dimensional immunoelectrophoresis.

The water-soluble components of Aspergillus fumigatus mycelium were partially separated by fractional precipitation with ammonium sulphate. The total protein and neutral-sugar content were determined for each of the four fractions prepared and their immunological activity was examined by double diffusion. Partial chemical characterisation of these isolates by polyacrylamide-gel electrophoresis was linked to their precipitability by allowing the separated components to diffuse from the gel into an agarose medium containing an appropriate antiserum. The distribution and reactivity of antigens was monitored by two-dimensional immunoelectrophoresis with rabbit sera raised against either mycelial or culture-filtrate antigens and human sera, obtained from patients with aspergilloma and from patients with allergic bronchopulmonary aspergillosis. This technique was also used to establish that considerable variation exists in the precipitation profile seen among patient specimens. Several antigens were found to possess sugar residues that interacted with concanavalin A, when this lectin was used in an intermediate gel in two-dimensional immunoelectrophoresis.