Carbohydrate-Carbohydrate Interaction: Zymosan and beta-Glucan from Saccharomyces cerevisiae Bind Mannosylated Glycoconjugates

E. V. Mikhalchik, S. D. Shiyan, and N. V. Bovin^*

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117434 Russia; fax: (095) 330-5592; E-mail: bovin@carb.siobc.ras.ru

^* To whom correspondence should be addressed.

Received June 29, 1999; Revision received January 15, 2000

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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.

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KEY WORDS: beta-glucan, glycoconjugates, yeast, zymosan, polyacrylamide, polysaccharides, carbohydrate-carbohydrate interaction

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