The Activity of Cilofungin on the Incorporation of Glucan Associated Proteins into Hyphal Cells of Candida albicans

Abstract

The effect of the cilofungin, a β 1-3 glucan synthase inhibitor, on the incorporation of the glucan associated proteins (GAP) into the mycelial wall of Candida albicans was investigated. For this study sub-inhibitory (< 2 μg/ml) doses of cilofungin were employed during the yeast to mycelial transition in a defined chemical medium, at 37°C for 24 hours. Under these conditions, and particularly at the dose of 0.50 μg/ml cilofungin exerted a marked effect on GAP incorporation into the mycelial cell wall. The changes were essentially the absence of the two prominent bands of 46 and 31 kDa of the untreated cell wall coupled with an apparent increase in the amount of 55-56 kDa constituent, as well as of a minor constituent of 27-28 kDa. Radiolabel incorporation experiments demonstrated increased synthesis of a 34 kDa GAP, in addition to confirming the absence of the 46 kDa constituent, in mycelial cells under cilofunging treatment. Thus, sub-inhibitory doses of cilofungin may greatly alter the pattern of essential cell wall constituents such as the glucan-associated proteins, suggesting that this drug also has important effects on cell wall structure and fine organization, independent of, or prior to, its principal lytic effect on the fungal organism.