Author Description

In order to develop a novel methodology for labeling on the PG at the conserved NAM residue to study the innate immune recognition of PG fragments, here I demonstrated the power of connecting the bacterial PG recycling program via enzymes AmgK and MurU, to the biosynthetic pathway to ultimately metabolically label bacterial PG with bioorthogonal handles. Using the synthetic modifiable NAM carbohydrate derivatives, these probes were installed into the backbone of Gram-positive and Gram-negative bacterial PG utilizing metabolic cell wall recycling and biosynthetic machineries. Whole bacterial cells are labeled via click chemistry and visualized using super-resolution microscopy, revealing higher resolution PG structural details and allowing the cell wall biosynthesis, as well as its destruction in immune cells, to be tracked. This method also provides a powerful tool for research on the bacterial cell division on the carbohydrate level. These studies will assist in the future identification of mechanisms that the immune system uses to recognize bacteria, glean information about fundamental cell wall architecture and aid in the design of novel antibiotics.