Changes in cell envelope glycoproteins during germ-tube formation of Candida albicans

Germ-tube formation by Candida albicans induced by N-acetylglucosamine resulted in the appearance of a 43 kD protein in a cell envelope fraction. The protein increased quantitatively in the cell envelope during the emergence of the germ-tube and the amount in the envelope fraction reflected the efficiency of the morphogenesis. The 43 kD protein was labelled by the lactoperoxidase catalysed iodination procedure confirming a surface location for the antigen. Concanavalin A binding to the 43 kD protein demonstrated that this protein contained carbohydrate. Tunicamycin inhibited both germ-tube formation in C. albicans and the appearance of the 43 kD protein in the cell envelope fraction. Instead the presence of tunicamycin resulted in the appearance of a new protein of 39 kD molecular weight in the cell envelope which did not bind concanavalin A. Endoglycosidase H digestion of the 43 kD protein produced a 39 kD protein. Peptide mapping of the 43 kD protein from germ-tube cells and the 39 kD protein from tunicamycin-treated cells indicated that these proteins are homologous.