Biotinylated Bi‐ and Tetra‐antennary Glycoconjugates for Escherichia coli Detection

Abstract

Glycans cover the surface of all mammalian cells. Several toxins and pathogens use these glycans to bind and infect the cell. Using a versatile modular synthetic strategy, we have developed biotinylated bi- and tetraantennary glycoconjugates to capture and detect E. coli and compared the capturing ability of these molecules to commercial polyclonal antibodies. Magnetic beads were coated with biotinylated glycoconjugate or antibody, and these beads were used to capture, isolate, and quantify bacterial recovery by using a luminescence assay. The glycoconjugate-coated magnetic beads outperformed antibody-coated magnetic beads in sensitivity and selectivity when compared under identical experimental conditions. Glycoconjugates could capture Escherichia coli from stagnant water, and the ability of a panel of glycoconjugates to capture a selection of pathogenic bacteria was also evaluated. To the best of our knowledge, this study represents the first comprehensive study that compares synthetic glycoconjugates and antibodies for E. coli detection. The glycoconjugates are also very stable and inexpensive. The results presented here are expected to lead to an increased interest in developing glycoconjugate-based high affinity reagents for diagnostics.

Factors Affecting Protein–Glycan Specificity: Effect of Spacers and Incubation Time

“…By using our previously described synthetic strategy, which has been successfully used to develop ligands for the capture of toxins, [10] viruses [11] and bacteria, [12] we constructed a panel of biotinylated S-sialosides that could adopt a variety of topologies ( Figure 1). The biotinylated S-sialosides, unlike naturally occurring O-sialosides, are impervious to cleavage by viral neuraminidase (NA) and therefore, can be used to analyze HA, NA, and intact virus.…”

Recent advances in biosensing using magnetic glyconanoparticles

“…In this sense, MNPs have the unique advantage than the bacteria attached to the glycoMNPs can be separated from the unbound ones just with a magnet. Pioneering work of El-Boubbou et al [66] and Hatch et al [67] demonstrated that MNPs functionalized with glycoconjugates could be used to isolate and quantify Escherichia coli, reaching higher sensitivity and selectivity than the same MNPs functionalized with antibodies [67]. Since then, some other examples where glycoMNPs are used to detect bacteria can be found in the literature [68].…”

Carbohydrate Mediated Bacterial Adhesion

“…decontamination. In a related study, much larger (2.8 μm diameter) magnetic particles 16 conjugated via a streptavidin monolayer were incubated with a mannose derivative linked to biotin (Hatch et al, 2008). The resulting particles were also used to detect E. coli.…”