Development of Metabolic Cell Wall Probes

Peptidoglycan is a polymer composed of two sugar monomeric units: N-acetyl glucosamine and N-acetyl
muramic acid. N-acetyl glucosamine is ubiquitously used across the broader living organismal kingdom.
Interestingly, N-acetyl muramic acid is solely used by bacteria making it the perfect candidate for
modification. We utilize chemical synthesis and genetic engineering to hijack the peptidoglycan
biosynthetic pathway to metabolically incorporate unnatural, yet “biorthogonal” derivatives of this
sugar. The biorthogonal probes we create give us the power to add labels – such as fluorophores or
affinity tags to the bacterial cell wall. We can then use these bacteria in a series of microscopy
experiments to visualize peptidoglycan uptake and digestion or harvest the material and any fragments
produced to biochemical investigate the process of bacterial cell wall degradation and investigate new
immunologically relevant structures, which could potentially lead to new antibiotic targets.