SURFACE-PROTEINS OF 2 AFLATOXIN-PRODUCING ISOLATES OF ASPERGILLUS-FLAVUS AND ASPERGILLUS-PARASITICUS MYCELIA .2. HPLC MAPPING BY GEL-PERMEATION, ION-EXCHANGE, AND REVERSE-PHASE CHROMATOGRAPHY

Surface mycelial proteins/peptides of Aspergillus flavus and Aspergillus parasiticus were extracted with phosphate-buffered saline and mapped by several chromatographic procedures. Molecular weights of mycelial proteins ranged from 200 Da to 100 kDa with major differences between species in the distribution of specific protein peaks. Cation exchange chromatography yielded at least 19 peaks for both fungal species, and at least two proteins, following isocratic elution from A. flavus, not detected in A. parasiticus mycelia were resolved by this procedure. Anion-exchange chromatography resolved 20 and 22 protein peaks in A. flavus and A. parasiticus extracts, respectively, but sizes and distribution of peaks of both basic and acidic proteins differed. Reverse-phase chromatography showed over 45 peaks in both fungi and revealed a cluster of 10 peaks in A. parasiticus that was not observed in A. flavus. These elution profiles reveal protein heterogeneity that might have application in the field of fungal taxonomy.