Molecular directionality in polysaccharide synthesis by glucosyltransferase

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We have developed a recipe for labeling reducing end of polysaccharide chains by reductive amination for microscopic visualization by TEM. This method was applied to investigate the following topics,1. Structure of native microfibrils and their directionality of synthesis.2. Chain packing in cellulose and chitin polymorphs3. Molecular directionality of enzymatic degradation4. Preference in binding modules of some cellobiohydrolases.1. The "parallel-up" structure was confirmed both for cellulose I and β-chitin. The polymerization of those chains was found to occur at non-reducing ends.2. Cellulose III was parallel while II was anti-parallel, which are in good accord with the previous studies on these polymorphs. However, the reducing end labeling of α-chitin was not in good accord with anti-parallel structure.3. Chitinase A and B from Serratia was found to digest b-chitin microfibrils from their reducing ends and non-reducing ends, respectively.4. Binding modules from some cellobiohydrolases showed preferential adsorption to the hydrophobic surface of cellulose : i.e. (100) surface of cellulose crystals.