Bacteria targeted by human natural antibodies using alpha-Gal conjugated receptor-specific glycopolymers.

Synthesis of polymerizable beta-lactosyl, Galalpha1-->3Gal and alpha-mannosyl acrylamide derivatives with either a hydrophobic aromatic spacer or a hydrophilic biocompatible oligoethoxyl spacer was accomplished. Radical terpolymerizations of beta-lactosyl monomer. alpha-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 alpha1-->3 galactosyltransferase to afford mediators bearing Galalpha1-->3Gal termini as xenoactive antigens and alpha-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 alpha-Gal containing glycopolymers and a monovalent alpha-Gal-Man glycoconjugate was demonstrated by an ELISA inhibition assay.