Inhibition of the dimorphic transition of Candida albicans by the ornithine decarboxylase inhibitor 1,4-diaminobutanone: alterations in the glycoprotein composition of the cell wall

Hyphal development in Candida albicans was selectively blocked by the ornithine decarboxylase competitive inhibitor 1,4-diaminobutanone (DAB). Inhibition of hyphal development required DAB during both yeast inoculum growth and subsequent incubation at 37 degrees C to induce mycelial growth. This effect was not due to general growth inhibition since DAB did not inhibit yeast growth, and reduced protein synthesis by 30% at most. Moreover, protein synthesis was unaffected by DAB when cells were pre-grown in drug-containing media. Since DAB inhibited dimorphic transition at 37 degrees C, morphology- and temperature-dependent protein synthesis could be distinguished. DAB stimulated the synthesis of several yeast wall-proteins, irrespective of morphology or growth temperature, and two at 37 degrees C only, but it inhibited the synthesis of a single mycelial-specific glycoprotein species.