Preliminary characterization of the material released to the culture medium byCandida albicans yeast and mycelial cells

Culture filtrate concentrates were obtained fromCandida albicans yeast and mycelial cells grown in the presence of¹⁴C-protein hydrolysate for radioactive labeling of cellular polypeptides. Both growth forms released to the medium minor but significant amounts of proteinaceous materials. The analysis of culture filtrate concentrates by means of SDS-polyacrylamide gel electrophoresis and fluorography revealed a similar and complex electrophoretic pattern, though some qualitative and quantitative differences between samples obtained from yeast and mycelial cells were observed. Materials released, mostly composed of mannoproteins as shown by their affinity towards concanavalin A, presented (i) cross-reactivity (by Western immunoblotting and ELISA) against polyclonal antisera to genuine cell wall components (among them the 58-kilodalton fibrinogen-binding mannoprotein) and (ii) high affinity for polystyrene-latex microbeads. Results presented suggest a possible common identity for the molecules shed to the medium and the cell wall protein and mannoprotein constituents.Abbreviations SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electroporesis - PAS periodic acid/Schiff method