Enzymatic synthesis of dendritic amphoteric α-glucans by thermostable phosphorylase catalysis

Abstract

This article reports the enzymatic synthesis of dendritic amphoteric α-glucans having both glucuronic acid and glucosamine residues at the non-reducing ends by thermostable phosphorylase-catalyzed successive glucuronylation and glucosaminylation of a glucan dendrimer having α-(1 → 4)-glucan non-reducing ends using α-D-glucuronic acid 1-phosphate and α-D-glucosamine 1-phosphate as glycosyl donors, respectively. The structure of the products is confirmed by the (1)H NMR analysis. The products exhibit inherent isoelectric points (pIs) determined by the ζ-potential measurement. These materials self-assemble in water at pH = pI to form large aggregates, but disassemble at pH shifted from pI.