Preparative isoelectric focusing of immunologically reactive components of Aspergillus fumigatus mycelium.

A water-soluble mycelial extract of Aspergillus fumigatus has been fractionated by preparative isoelectric focusing using carrier ampholytes in a layer of granulated gel. The separated components were located by staining paper prints from the gel. Within a narrow pH range of 2.5 units, multiple protein bands were visualized with Coomassie Brilliant Blue G. Periodate-Schiff-positive material was generally associated with the major protein zones. When these fractions were eluted the total recovery, calculated on the basis of protein and carbohydrate analyses of the isolated fractions, varied between 20 and 60% of the applied material. Low recoveries were associated with low recoveries of protein; recoveries of carbohydrate were higher and less variable. The immunological activity and specificity of the eluted fractions were assessed in an enzyme-linked immunosorbent assay for the detection of IgG antibodies to A. fumigatus.