EXPRESSION PATTERN OF ASPARTIC PROTEINASE ANTIGENS IN ASPERGILLI

Sporulating colonies of Aspergillus fumigatus, A. flavus, and A. niger were subjected to immunofluorescence using specific polyclonal antibo dies against the aspergillopepsin PEP (EC 3.4-.23.18), a secretory asp artic proteinase produced by A. fumigatus. The proteinase antigen was found mainly in developing conidiophores of aspergilli, in submerged m ycelia and on the tips of growing aerial mycelia. Mature aerial hyphae and spores showed no immunofluorescence at all. Sporulating conidioph ores revealed only weak activity in A. fumigatus and A. flavus. The di stinct pattern of expression of the aspartic proteinase antigens sugge sts a role for such enzymes in the growth of hyphae and the developmen t of conidiophores and thus for the sporulation process in aspergilli.