REAGGREGATION AND BINDING OF CELL-WALL PROTEINS FROM CANDIDA-ALBICANSTO STRUCTURAL POLYSACCHARIDES

Urea or hot sodium dodecyl sulphate extracted a significant amount of the same proteins from the matrix of the cell wall of the yeast form a nd mycelial cells of Candida albicans. Gel filtration analysis of the urea-extracted proteins revealed that they occurred in the form of lar ge complexes which were unaffected by up to 8 M urea. Among them, prot eins en route to becoming covalently associated within the wall scaffo ld were identified by their reaction with specific antibodies. When ur ea was removed by dialysis, some of these proteins specifically reasso ciated into large aggregates which bound strongly with ConA, whereas o thers remained soluble in smaller associated products. The ability of some of these proteins to bind to the insoluble wall polysaccharides w as also assessed. No self-assembling proteins were able to bind to glu cans and/or chitin. Specificity of the binding to polysaccharides made of beta-bound glucosyl or N-acetylglucosaminyl residues was determine d by the competitive effect of several disaccharides, Whereas laminari biose and diacetylchitobiose were strong inhibitors of protein binding to both glucan and chitin, lactose, maltose and sucrose were ineffect ive.