THE ACTIVITY OF CILOFUNGIN ON THE INCORPORATION OF GLUCAN ASSOCIATED PROTEINS INTO HYPHAL CELLS OF CANDIDA-ALBICANS

The effect of the cilofungin, a beta 1-3 glucan synthase inhibitor, on the incorporation of the glucan associated proteins (GAP) into the my celial wall of Candida albicans was investigated. For this study sub-i nhibitory (< 2 mu g/ml) doses of cilofungin were employed during the y east to mycelial transition in a defined chemical medium, at 37 degree s C for 24 hours. Under these conditions, and particularly at the dose of 0.50 mu g/ml cilofungin exerted a marked effect on GAP incorporati on into the mycelial cell wall. The changes were essentially the absen ce of the two prominent bands of 46 and 31 kDa of the untreated cell w all coupled with an apparent increase in the amount of 55-56 kDa const ituent, as well as of a minor constituent of 27-28 kDa. Radiolabel inc orporation experiments demonstrated increased synthesis of a 34 kDa GA P, in addition to confirming the absence of the 46 kDa constituent, in mycelial cells under cilofunging treatment. Thus, sub-inhibitory dose s of cilofungin may greatly alter the pattern of essential cell wall c onstituents such as the glucan-associated proteins, suggesting that th is drug also has important effects on eel wall structure and fine orga nization, independent of, or prior to, its principal lytic effect on t he fungal organism.