Preparation of pH-Responsive Amphoteric Glycogen Hydrogels by -Glucan Phosphorylase-Catalyzed Successive Enzymatic Reactions

摘要

The thermostable -glucan phosphorylase-catalyzed enzymatic -glucuronylation and subsequent -glucosaminylation of glycogen using -d-glucuronic acid 1-phosphate (GlcA-1-P) and -d-glucosamine 1-phosphate (GlcN-1-P), respectively, produce amphoteric glycogens. The products exhibit the inherent isoelectric points, which change depending on the GlcA/GlcN ratios. Chain elongation of amyloses from the nonfunctionalized, nonreducing ends of the products through the thermostable -glucan phosphorylase-catalyzed enzymatic polymerization of -d-glucose 1-phosphate monomers is demonstrated to yield amphoteric glycogen hydrogels. The produced hydrogels exhibit pH-responsive behavior.