REDUCTIVE CLEAVAGE METHOD FOR GLYCAN STRUCTURAL ANALYSIS

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The determination of structure of complex carbohydrates is an important problem in many areas of biomedical investigation because of their involvement in cellular recognition processes, their role as structural materials, and their presence as antigenic determinants in tumors, bacteria, fungi, and viruses. Because of their structural complexity, no single method for establishing their structure is available. The myriad of chemical methodologies currently available are very laborious and ambiguous results are often obtained. We therefore began a program to develop a new method for the structural characterization of complex glycans that would overcome the difficulties associated with current methodologies. The structural method that forms the basis of this proposal is referred to as the "Reductive Cleavage Method" because its salient feature is the regiospecific reductive cleavage of all glycosidic bonds in a fully methylated polysaccharide. This method is substantially different than "methylation analysis", however, because 1) all linkage positions and ring forms in a polysaccharide are established simultaneously, and 2) conversion of the fully methylated polysaccharide to derivatives suitable for separation and analysis is accomplished in a one-past work, we feel that the Reductive Cleavage Method has the potential to serve as a general method for the structural characterization of all complex carbohydrates, to include establishing the identities of constituent monomers, their ring form, their position(s) of linkage, their anomeric configuration, and their sequence. Experiments designed to examine the feasibility of this approach form the basis of this proposal. The research proposed herein therefore has as its objectives the integration of the Reductive Cleavage Method into a simplified scheme for complex carbohydrate structural analysis.