Synthesis of Hyperbranched Glycoconjugates by the Combined Action of Potato Phosphorylase and Glycogen Branching Enzyme from Deinococcus geothermalis

Abstract

Abstract:Potato phosphorylase is able to synthesize linear polyglucans from maltoheptaose primers. By coupling maltoheptaose to butane diamine, tris(2-aminoethyl)amine and amine functionalized amine functionalized poly ethyleneglycol (PEG), new primer molecules became available. The resulting di-, tri-and macro-primers were incubated with potato phosphorylase and glycogen branching enzyme from Deinococcus geothermalis. Due to the action of both enzymes, hyperbranched polyglucan arms were grown from the maltoheptaose derivatives with a maximum degree of branching of 11%. The size of the synthesized hyperbranched polyglucans could be controlled by the ratio monomer over primer. About 60%-80% of the monomers were incorporated in the glycoconjugates. The resulting hyperbranched glycoconjugates were subjected to Dynamic Light Scattering (DLS) measurements in order to determine the hydrodynamic radius and it became obvious that the structures formed agglomerates in the range of 14-32 nm.

Synthesis and Self-Assembly of Double-Hydrophilic and Amphiphilic Block Glycopolymers

“…The decay rate of the distribution function was fitted linearly against the q 2 (Figure 5a) and the slope of this plot was attributed to the translational diffusion coefficient parameter ( D t ) in eq 1. 48,49 Using the gained D t , hydrodynamic diameter of the micelles were calculated by the Stokes–Einstein Equation (eq 2), and the numbers are shown in Table 3.…”

Physical properties and structure of enzymatically synthesized amylopectin analogs

“…The biocatalytic synthesis of (branched) polysaccharides was proven to be highly successful [9,[14][15][16]. Such synthetic polysaccharides can be used in different fields; such as hyperbranched glycoconjugates for drug delivery purposes; or enzymatically synthesized glycogens as anti-tumor agents [15,17] or as standards for new characterization protocols for branched polysaccharides [17]. The complete mechanism of the tandem enzymatic polymerization with phosphorylase and branching enzyme is not known yet; nevertheless, in our previous work, we unraveled parts of the mechanism by an in-depth characterization of synthetic amylopectin analogues using SEC with multi-detection in combination with the analysis of enzymatically debranched molecules using MALDI-ToF MS [16].…”

“…The biocatalytic synthesis of (branched) polysaccharides was proven to be highly successful . Such synthetic polysaccharides can be used in different fields; such as hyperbranched glycoconjugates for drug delivery purposes; or enzymatically synthesized glycogens as anti‐tumor agents or as standards for new characterization protocols for branched polysaccharides .…”

Green Synthesis of Glycopolymers Using an Enzymatic Approach

“…The group of Reimund Stadler was working extensively on glyco‐hybrid structures such as carbohydrate/polysaccharide modified polysiloxane brush systems, polystyrene rod‐coil systems, and modified surfaces . This work was extended in recent years to continue the efforts of the Stadler group …”