Calander Home 2001-2002 2002-2003 Dr. Gary Gray The Reductive Cleavage Method for Carbohydrate Structural Analysis Date: February 2 Time: Noon to 1 Place: BSBE 4-101 The major thrust of recent work in my laboratory has been the development of new methods for the structural characterization of carbohydrate polymers. The determination of structure of these materials is an important problem in many areas of biomedical investigation because of their involvement in cellular recognition processes, their presence as antigenic determinants in tumors, bacteria, fungi, and viruses, and their involvement as recognition elements in bacterial and viral infections. Carbohydrate polymers and various chemically-modified derivatives are also very important industrial products, so methods for their structural characterization play an important role in the development of new products and in quality control in the manufacture of existing products. Because of the structural complexity of these polymers, many chemical and spectroscopic procedures have been developed for their compositional and structural analysis. However, these procedures are very laborious and, in many cases, are not generally applicable to all classes of monosaccharides or to all combinations of the structural features that can be encountered. In response to the shortcomings of existing methods for polysaccharide structural analysis, we have developed a new method that can simultaneously establish the identity and ratio of each sugar as well as the ring form and linkage position(s) of each sugar residue. We refer to this method as the "Reductive-Cleavage Method" because its salient feature is the regiospecific reductive cleavage of all glycosidic linkages in a fully methylated polysaccharide. We have already demonstrated that the method is applicable to all classes of monosaccharides that are found as constituents of these polymers and we are presently developing the method with regard to its potential for sequence determination. Toward the latter end, we are developing methods for selective reductive cleavage based either on the chemical properties of the various classes or sugars or the reactivities of the reagents used to accomplish reduction of glycosidic linkages. Guiding the further development of the method is its application to the analysis of several polysaccharides of biological and industrial significance.