A New Type of Artificial Glycoconjugate Polymer:  A Convenient Synthesis and Its Interaction with Lectins

Abstract

A convenient synthetic route to a new type of artificial glycoconjugate polymer has been designed to develop biomedical materials using oligosaccharide moieties as recognition signals. An amino function was introduced to the reducing end of lactose and N,N‘-diacetylchitobiose with ammonium hydrogen carbonate and then was allowed to react with p-vinylbenzoyl chloride. The N-glycosidation proceeded stereospecifically in one flask to give only the β-glycoside without any protection and deprotection steps. The resulting p-vinylbenzamide glycoside derivatives were homo- and copolymerized with acrylamide using 2,2‘-azobisisobutyronitrile as initiator in dimethyl sulfoxide at 60 °C. The interaction of the glycopolymers with lectins was investigated by means of a two-dimensional immunodiffusion test in agar and inhibition of the hemagglutinating activity. The specificity of lectins with these glycopolymers was similar to that reported for naturally-occurring glycoconjugates. Binding between wheat germ agglutinin lectin (WGA) and poly((p-vinylbenzamido)-β-diacetylchitobiose) was increased by 103 times compared with that of the oligosaccharide itself. The enhancement was attributed to the presence of the hydrophobic phenyl aglycon as well as the high density, multiantennary disaccharide ligands along the polymer chain. The present synthetic method is useful to introduce biologically important, complex oligosaccharides into glycopolymers.

Purification, Characterization, and Sugar Binding Specificity of an N-Glycolylneuraminic Acid-specific Lectin from the Mushroom Chlorophyllum molybdites

“…were synthesized as described previously (22,23). All other sugars and glycoproteins for the sugar analysis, the hemagglutinating inhibition tests, and the SPR analyses were products of Nacalai Tesque (Japan), Wako Pure Chemical (Japan), Calbiochem, or Sigma.…”

Self-aggregate nanoparticles of cholesteryl and galactoside groups-substituted pullulan and their specific binding to galactose specific lectin, RCA120

“…Affinity of saccharide determinants for lectins 26,27) or receptors on a viral surface 28) drastically increases upon the substitution to polymer. We estimated the binding constants between a specific lectin and each saccharide attached to the polymer by the competitive titration method using a fluorescent ligand 18,19) .…”

Glycodynamers: Fluorescent Dynamic Analogues of Polysaccharides

“…These dimensions are in agreement with the expected diameter of a single polymer chain with a bottlebrush-like shape, as reported for single polystyrene chains decorated with similar oligosaccharide side chains. [25] Such a shape can be expected to confer interesting biorecognition properties to the resulting glycopolymer, as previous examples of this type of polymer were found to have the potential to bind lectin [26] and were used as cell-culture media. [27] Whereas 2 a was the only monomer to show significant fluorescence, all four polymers displayed remarkable fluorescence, with emission ranging from blue for 1 a·2 b (l max = 457 nm) to green for 1 a·2 a (l max = 495 nm) and 1 b·2 b (l max = 499 nm), and to red for 1 b/2 a (l max = 567 nm; Figure 1).…”