The immunochemical techniques of quantitative precipitation and hapten inhibition have been employed in a study of the interaction of concanavalin A with several.levans of bacterial and plant origin. Of the polysaccharides that form a precipitate with concanavalin A (dextrans, D-mannans,

The immunochemical techniques of quantitative precipitation and hapten inhibition have been employed in a study of the interaction of concanavalin A with several.levans of bacterial and plant origin. Of the polysaccharides that form a precipitate with concanavalin A (dextrans, D-mannans, glycogens, amylopcctins, and levans), levans appear to be the least reactive. Hapten-inhibition studies were conducted with a wide variety of compocmds containing a furanoid ring. As a generalization, it may now be stated that all sugars containing the 1,4-anhydro-D-arabinitol moiety can bind to the active sites of concanavalin A. Because evidence from this laboratory suggests that the interaction of concanavalin A with reactive polysaccharides occurs at the same binding sites of the protein, reaction with levans may be rationalized on the basis of common configurational features_ The disposition of the hydroxyl groups on C-3, C-4, and C-6 (or C-l, C-3, and C-4) of the B-D-fructofuranosyl moiety, which is the residue that occurs at chain ends of levans, is similar to that on C-3, C-4, and C-6 of the CL-Dglucopyranosyl moiety, the sugar residue found at the chain ends of a-D-glucans.