Protein---carbohydrate interaction. : Part XXII. A chemically-synthesized d-mannan and the interaction of some synthetic d-mannans with concanavalin A

Abstract

1,6-Anhydro-[beta]--mannopyranose was polymerized in the presence of chloroacetic acid. A high-molecular-weight fraction insoluble in 80% ethanol was isolated and studied. Periodate-oxidation studies showed the polymer to contain 42% of (1-->6)-like linkages, 36% of (1-->4)- or (1-->2)-like linkages, and 22% (1-->3)-like linkages. End-group analysis gave = 113. The synthetic -mannan reacted vigorously with concanavalin A, indicating that it was a highly branched polymer containing multiple [alpha]--mannopyranosyl residues at chain ends. A synthetic -mannan obtained by the polymerization of -mannose in the presence of phosphorous acid gave a much weaker reaction with concanavalin A, and two synthetic, linear polymers failed, as expected, to form a precipitate with this plant protein.