Bacteria targeted by human natural antibodies using α-gal conjugated receptor-specific glycopolymers

Abstract

Synthesis of polymerizable β-lactosyl, Galα1→3Gal and α-mannosyl acrylamide derivatives with either a hydrophobic aromatic spacer or a hydrophilic biocompatible oligoethoxyl spacer was accomplished. Radical terpolymerizations of β-lactosyl monomer, α-mannosyl monomer, and acrylamide were conducted in aqueous media with ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine as initiators. The resulting water soluble glycopolymers were further transformed efficiently by a recombinant α1→3 galactosyltransferase to afford mediators bearing Galα1→3Gal termini as xenoactive antigens and α-mannosyl termini as specific ligands for bacterial cells. The binding of the resulting multivalent glycopolymer to bacteria was tested by its ability to inhibit agglutination of yeast to E. coli. The binding of human natural anti-Gal antibodies to the α-Gal containing glycopolymers and a monovalent α-Gal-Man glycoconjugate was demonstrated by an ELISA inhibition assay.