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Item Mannose-functionalized PAMAM dendrimers : their synthesis, characterization and use in refining the model of protein-carbohydrate interactions(Montana State University - Bozeman, College of Letters & Science, 2003) Woller, Eric KevinItem The preparation of synthetic mustard oil glycosides and the specificity of the myrosinase system(Montana State University - Bozeman, College of Letters & Science, 1960) Gaines, Robert D.Item Palladium (II)-catalyzed stereoselective formation of [alpha]-O-glycosides(Montana State University - Bozeman, College of Letters & Science, 2007) Schuff, Brandon Patrick; Chairperson, Graduate Committee: Hien NguyenThe development of new methods for stereoselective formation of a- or *-Oglycosides has been extensively investigated due to the critical roles carbohydrates play in a variety of biological systems. To date, many efforts have focused on developing new methods and reagents for the generation of isolated glycosyl donors which subsequently undergo glycosidic bond formation with nucleophilic glycosyl acceptors. Despite their potential applications to complex carbohydrate synthesis, each of these methods relies on the nature of the substrates to stereoselectively control the formation of glycosidic bonds. Recently, the use of glycal derivatives as glycosyl donors has been utilized in p- allylpalladium strategies for the stereoselective synthesis of O-glycosides. However, due to the poor reactivity of the glycal donors as well as the alcohol nucleophiles, these groups utilized the more activated pyranone donors. Lee, who recognized the challenge in this approach, utilized Zn(II) ion to activate both the alcohol acceptors for the nucleophilic addition and the glycal donors for the ionization.Item Using PAMAM dendrimer frameworks to investigate multivalent binding in protein-carbohydrate interactions(Montana State University - Bozeman, College of Letters & Science, 2009) Wolfenden, Mark Leroy; Chairperson, Graduate Committee: Mary J. CloningerPolyvalent interactions in biological systems have been of great interest recently; how nature creates high affinity polyvalent binding with low monomeric affinity, is yet to be clearly understood. We have created a bivalent lectincarbohydrate binding 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: mannose binds 4 times stronger than glucose, and galactose shows no affinity. With these relative affinities in hand and changing the ratios of mannose, glucose and galactose on the periphery of the PAMAM dendrimer scaffold, we have made a predictable and tuneable system with which to control the polyvalent binding relative affinity. By changing the carbohydrate presentation and varying the size of 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. In exploring more complex lectin : carbohydrate systems we have made a library of lactose, galactose and galNAc functionalized dendrimers to study binding to galectin-3. This lectin is implicated in numerous cancer related pathway, cellular proliferation and apoptosis. An ELISA based assay was developed to gain binding information of this intruiging interaction. The assay results suggest a reduced effect of binding association even with a large range of monomeric affinities, indicating a multivalent system. The monomer affinities did however affect the lectin recruitment to the dendrimers adsorbed onto a surface. The report here indicated a delicate interplay of modes of multivalent binding that dictate the biological behavior of this important galactose binding lectin.