Protein-Carbohydrate Interaction

Summary The extent to which a number of saccharides inhibit concanavalin A-dextran interaction has been examined by means of the quantitative hapten inhibition technique involving nitrogen analyses of washed precipitates. The results of these studies are in essential agreement with previous studies employing a turbidimetric procedure. The combining sites of the concanavalin A protein molecule are shown to be complementary to the C-3, C-4 and C-6 hydroxyl groups of α-D-glucopyranosyl and α-D-mannopyranosyl units. Any modification of the C-6 hydroxyl group of methyl α-D-glucopyranoside virtually eliminates the capacity of the resultant sugars to bind to the combining sites of concanavalin A. On the basis of these data it is concluded that the H-atom of the C-6 hydroxyl group forms a hydrogen bond with the protein.