Protein-carbohydrate interaction , : XVI. The interaction of concanavalin A with dextrans from L. mesenteroides B-512-F, L. mesenteroides (Birmingham), Streptococcus bovis, and a synthetic [alpha]-(1 --> 6)--glucan

Abstract

The precipitation reaction between concanavalin A, the jack-bean hemagglutinin and several dextrans has been examined by means of the quantitative precipitin technique. A synthetic linear [alpha]-(1 --> 6)--glucan did not form a precipitate with concanavalin A, demonstrating that only branched [alpha]--glucans precipitate with the protein.The dextran from Streptcoccus bovis produced a typical precipitation curve with concanavalin A and gave the disaccharide nigerose when subjected to acetolysis. On the basis of these data it is suggested that this dextran, hitherto believed to be linear, is in fact a branched polymer.The concanavalin A precipitation curves of the dextrans from Leuconostoc mesenteroides NRRL B-512-F and Betacoccus arabinosaceous (L. mesenteroides) Birmingham strain were compared with the S. bovis dextran and an attempt has been made to correlate these data with the molecular structures of these dextrans. The differences in the solubility of the dextran-concanavalin A precipitates and the relative ease of inhibition of these systems in the presence of hapten inhibitor are also discussed.