Bacterial toxins have efficiently evolved to effectively gain entry into host organisms. Infection often leads to diarrhoeal disease, dehydration and potential death.1 The AB5 family of toxins, contain a pentameric B-subunit binding lectin which binds cell surface glycolipids.2 Binding multiple copies of the glycolipid gives rise to very high affinity interactions, which aids the cellular uptake of the toxin.3 Inhibiting these interactions would lead to prevention of toxin entry and disease. Site specific modification of the cholera toxin B-subunit has shown to present carbohydrates with optimal geometry and valency for toxin binding, and an attractive method of creating complex multivalent inhibitors.4 Here, we present the use of novel bi-functional, bio-orthogonal linkers for the functionalisation of oligosaccharides for the glycosylation of mutant bacterial B subunits. The novel linker can be used neoglycoproteins bearing different oligosaccharides on different faces of the proteins, for the generation of bacterial toxin inhibitors against various toxins.
Multiple site functionalisation of a protein scaffold, with chemically reactive globotrioside (Gb3) and GM1 pentasaccharide using a single Bicyclononyne (BCN) linker.
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