Carbohydrate-carbohydrate interaction: zymosan and beta-glucan from Saccharomyces cerevisiae bind mannosylated glycoconjugates.

Zymosan from cell wall of the yeast Saccharomyces cerevisiae was found to interact with synthetic and natural glycoconjugates; mannose-rich glycoprotein N-chains demonstrated the maximal affinity. The carbohydrate-carbohydrate nature of the interaction has been confirmed by the following data: 1) periodate treatment of the zymosan impairs the binding; 2) neither protease nor alkali treatment of the zymosan weaken the binding; 3) beta-glucan from S. cerevisiae, which is the major zymosan component, interacts with glycoconjugates similarly to zymosan. The binding is reversible, Ca2+-dependent, and cooperative; it can be dose-dependently inhibited by saccharides relative to one of the partners of the carbohydrate-carbohydrate interaction.