Antibiotic resistance is becoming an increasing threat to global health. This fellowship aims to produce
inhibitor libraries that target enzymes associated with bacterial survival and ultimately antibiotic resistance.
Nucleoside natural products have shown biological activity towards bacterial cell wall synthesis, making them
excellent scaffolds for inhibitor development. However, the complexity of these natural products makes
synthesis, controlling selectivity, and minimizing toxicity a challenge. The family of enzymes that are targeted in
this proposal are monotopic phosphoglycosyl transferases (PGTs). These PGTs are enzymes that catalyze the
initial step in the synthesis of glycoconjugates that are linked with bacterial virulence. Once a set of inhibitors are
synthesized, they will be tested with biochemical assays with various monotopic PGTs to establish their IC50 and
Kd values. However, a major limitation with antibiotic development is the inability of some inhibitors to traverse
the membrane and accumulate in Gram-negative bacteria. For that reason, the inhibitors will be tested for cellular
uptake in Gram-negative bacteria and quantified using liquid chromatography coupled with mass spectroscopy
(LC-MS). Lastly, chemoenzymatic syntheses of a UDP-sugars, will be performed and used in combination with
biochemical assays to aid in the characterization of a monotopic PGT. The culmination of the work proposed in
this fellowship will contribute to the development of effective inhibitors targeting monotopic PGTs, which will
provide tools to study glycoconjugate biosynthesis and ultimately aid in the fight against antibiotic resistance.