ANALYSIS OF PEPTIDOGALACTOMANNANS FROM THE MYCELIAL SURFACE OF ASPERGILLUS-FUMIGATUS

Peptidogalactomannans (pGMs) from mycelium of two strains of Aspergill us fumigatus were fractionated by Cetavlon precipitation and size excl usion chromatography and their carbohydrate structures analysed using methylation-fragmentation analysis, partial acetolysis and C-13-nuclea r magnetic resonance spectroscopy. The most significant difference bet ween the pGMs of the two strains was the degree of branching and the p roportion of non-reducing ends of alpha-D-Manp and beta-D-Galf units. Methylation data showed that the pGM from AF 2109 contained alpha-D-Ma np and beta-D-Galf non-reducing end units in a proportion of 3:1 while , in contrast, the proportion of these structures in pGM from AF 2140 was 7:1, resulting in a highly branched structure. The immunoreactivit y of the pGM fractions was tested by indirect immunofluorescence. The fractions were also tested in an ELISA system with rabbit antiserum ra ised to whole cells of A. fumigatus NCPF 2140 and with serum from pati ents with either proven aspergilloma or ABPA. The carbohydrate moiety of the pGM appears to be responsible for the antigenicity. Periodate t reatment, partial acid hydrolysis and beta-elimination removed most of the antibody binding capacity.