Mannose/glucose functionalized dendrimers as tools for probing tunable multivalency

BIOL 129

Mark L. Wolfenden, mwolfenden2000@yahoo.com and Mary J. Cloninger, mcloninger@chemistry.montana.edu. Department of Chemistry and Biochemistry and Center for Bioinspired Nanomaterials, Montana State University, Bozeman, MT 59717
Polyvalent interactions in biological systems have been of great interest recently and are not yet fully understood. We have created a bivalent lectin-carbohydrate system using dendrimers as the carbohydrate mounted scaffold and Concanavalin A (Con A) as the mannose/glucose binding lectin to investigate this mode of interaction. The relative affinities of the utilized carbohydrates toward Con A are as follows: mannose binds with 4 times higher affinity than glucose, and galactose does not bind. Changing the ratios of mannose, glucose, and galactose on the periphery of the PAMAM dendrimer scaffold, we have made a predictable and tunable system with which to control the relative polyvalent binding affinity. By changing the carbohydrate presentation and varying the size of the PAMAM dendrimer used, we can tune the affinity between two orders of magnitude. Although the relative affinities can be predictably altered, the clustering ability across the same generation dendrimer is not affected.