Activation of Biofunctional Molecules Induced by Binding of Glycomolecules

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First, the reaction which binds oligosaccharides to peptides in mild conditions was examined. Malto-oligosaccharides having 2-7 glucose residues were found to the amino group of polylysine or polyarginine as protein model compounds by use of sodium cyanoborohydrate as a reducing agent at 37ﾟC for several hours. Since in NMR spectra of the reaction products, absorptions due to epsilon-carbon of poiyilsine side chains shifted from the original position at 40.9ppm to 50.2ppm, the ratio of each peak intensity was determined. Reaction conditions affording high degrees of substitution of 85-90% were found by using 10 equivalents of oligosaccharides such as maltose and maltopentaose.Next, bindings of oligosaccharides to natural enzymes such as aldolase, lactate dehydrogenase, 6-phosphogluconic dehydrogenase, cholinesterase, and phosphatase slkaline were performed. All sugar bound-enzymes except for aldolase (9%) exhibited58-90% of their original activities. In the case of maltose or maltoheptaose bound-phosphatase alkaline, it was found that, the enzyme activity after 10-20 days was much larger than that of the original phosphatase slkaline.In addition, to examine mechanisms of interactions of poilsaccharides with proteins, various mixtures of suifated polysaccharides such as curdlan sulfate, heparin, and chondroitin sulfate with polypeptide like polylysine, polyarginine, and their copolymers were measured by NMR.